In an attempt to help her new mentor and best friend Billy, Lizzie Spaulding plotted with Bill’s sister Dinah Marler to have him come back to Springfield to reconcile with his father. Little did they knew that Bill Jr. had no plans of reconciling with his Dad, and in fact came back with a dark agenda of his own.
The first time the two saw each other as adults, Bill walked out of Lizzie’s bathroom wearing nothing but a towel. Obviously flustered and attracted, Lizzie tried to busy herself with attempting to call Bill’s father to tell him the good news that his son was home. Bill took the phone, and the two locked eyes chemically. He asked her not to tell his father, because he wanted it to be a surprise.
Since Dinah was Lizzie’s new roommate, and Bill was Dinah’s brother and had no immediate place to live, Lizzie allowed him to move in as well.
Angry with his father for ousting him from the family business, and taking Lizzie under his wing as his new protégée, Bill plotted to mess this up. While alone in Lizzie’s room, he came across her diary, and eagerly read it to get the scoop on her. He laughed at the comical parts (about clothes, tanning, her dog Roxie, etc) but seemed to be visibly affected (if only a bit) at the parts where she talked about being lonely, and missing her daughter and former husband, who had ‘died’ a year before. Not affected enough to really care, Bill used the knowledge garnered to fool Lizzie into thinking he was her ‘perfect man’, and even stood up to her grandfather to seal the deal. Dying for romance and love, and fooled by Bill’s sweet words, Lizzie gave into his kiss. The two proceeded to go back to their room, passionately pawing at each other the whole way, where they made love.
While Lizzie slept, Bill crept out from under her, leaving her sleeping, and stole her project information. She slept in and was late for her press conference, and when she got there, she found that Bill had stolen the deal from her and wowed the buyer himself. Due to the popularity and success he gained, Billy was forced to rehire his son. Much to Lizzie’s chagrin, she now had to work with her seducer.
For months, the pair would go back and forth over the lines of like and dislike. They would share a close moment, just to have one burn the other one again. Though they were feeling their attraction, both were set on doing the other in. Bill to get Lizzie out of his family, and Lizzie to get Bill back for lying to get her in bed.
Dinah warned Bill to not really fall for Lizzie, as it would get in the way of their plot to get back at his Dad. Bill assured her his feelings for Lizzie were not real, and he knew what he was doing. The next day he fired Lizzie from Lewis, as he figured he was in charge now that his Dad was in rehab. Bill tried to give her flowers and convince her that now they could see each other, but Lizzie didn’t believe him, and pushed out of her room telling his she hated him for making her care again.
Bill’s plot to oust her fell flat though when Billy relinquished the company to his brother Dylan Lewis, and made Lizzie Dylan’s number two. Lizzie and Dylan decided to work together to foil Bill’s plans.
However, the very next week, while Bill worked on Doris Wolfe’s Main Street plans, Lizzie came to the construction site. The two flirted in the trailer, and Bill even broke things off with his sex buddy Ava in order to be with Lizzie. She told him if he would get rid of the Main Street project (which would hurt many town residents) he could have her. Teasingly kissing him, Lizzie convinced Bill to come back to his room where they immediately began undressing each other. Lizzie asked Bill to be honest with her and tell her that he wanted her. Bill did, but turned it into a joke about being committed to getting her clothes off. The two continued to go at it until they were down their skivvies. Lizzie told Bill they could be good together if only he really wanted her. Bill swore he did, and told her to let him show her exactly how much.
Lizzie insisted on changing into something sexier before they continued. When she rentered she said she didn't want them to get into a rut, and wanted this time to be exciting for them. Bill suggested the floor, the desk, and the shower. Lizzie wanted to make love on the balcony. Bill protested that it was too cold, but when she called him a chicken, he pulled her toward the balcony passionately. As soon as he was on the stoop, Lizzie slammed the door behind him, and locked him out. She left him to find his way back inside himself, but when she found her picture in his wallet, she went back to release him, but he'd already made an escape.
That same night, Lizzie went looking for Bill again at the construction trailer. What she didn't know is that a drunken and emotional Coop, angry at Doris and Bill over their plans to hurt his family, had lit a set of plans on fire and tossed them in Bill’s trailer (not knowing he was inside) Just as Lizzie approached, the building had an explosion. A shocked Lizzie called 911, and took care of Bill as they waited. She stuck with him aand tried to help him after he was blinded, but angry over his condition, he refuted her help, and turned to causal sex in Ava.
A distraught Lizzie sought comfort in Reva, who insisted on taking Lizzie to the hospital when she complained of severe stomach pains and almost fainted. The doctor told Lizzie she could be pregnant, and Lizzie rushed to tell Bill. She stopped him from setting Company on fire in retaliation for his blindness, and told him he was going to be a father.
Bill does not believe Lizzie, as she lied to Coop about a pregnancy before. Lizzie protested that she did not lie about being pregnant, she would never do that, she only lied about the father. Bill tells her he still doesn’t believe her because he says this all in their little cat and mouse game, and she just wants a reaction from him. He tells her if he could see her face he would know she was lying. Lizzie puts her hands on Bill’s and pulls them to cup her face, and tells him that’s how he can ‘see’ her. Bill feels her hands shaking against his, and finally takes her seriously. He tells her he is not be ready to be a father, and asks her if she really wants a blind screw up like him in her kids life anyway. Lizzie says she wants it more than anything, and the two lie on Bill’s bed and share a close moment talking about the hope that comes with their baby. And even though it’s early, Lizzie puts Bill’s hand on her tummy where their child is likely growing. Bill smiles, but appears nervous.
The next morning, Lizzie is still excited, but Bill has grown more nervous and tells Lizzie he doesn’t think he’s ready for this. He tells her he will financially support the baby, but he isn’t ready to be the kid’s father, or to be with her. Lizzie lashes out and tell him to grow up and be a man. He tells her he’s at least better than her former conquests (Coop and Jonathan) She gets very angry at him talking about her deceased former husband, and tells him that Jonathan was one thing Bill will never be, a great father to her baby.
After finding out about the pregnancy, an excited Billy urges Bill to make this right and start a family with Lizzie. Bill continues to rebuff the idea, until he learns he stands a chance of getting his eyesight back. At Tammy’s memorial, Bill approaches Lizzie (who has found out she is not pregnant) and he attempts comfort her and strokes her face, but she cringes from him confused by his change in attitude. Bill insists that he acted rashly, and he sincerely wants to be happy with her and their child. Lizzie almost tells him about not being pregnant, but after hearing him actually say he wants her, she is unable to.
Bill regains his sight, and sees Jonathan at the church, but says nothing. It is implied he did this because he is jealous of even the very memory of Jon, and doesn’t want Lizzie to be stuck on him. He tells Lizzie he wants their past to be their past, and their future their future. They head to Bauer Cabin to get away and think. While there, Lizzie attempts to seduce Bill in order to have the baby he now wants. He is set on just talking though, about their future and their baby. Lizzie freaks, tells him there is no baby, and runs. He chases her, but she struggles away and falls into traffic, and is saved by Jonathan.
Bill is obviously severely jealous of Jon from the moment he renters the picture. Lizzie inquires about how he survived, and Jon lies and says only he survived, but Sarah was killed. Lizzie is distraught, and Bill orders Jonathan to leave. To Bill’s displeasure though, Lizzie latches on to Jon and begs him to stay with her, him being the last part of Sarah she has left. The two men argue over who has hurt Lizzie worse, but Lizzie is only interested in reminiscing about her baby girl. Jonathan claims he must go, and Lizzie tearfully allows him. Jonathan instructs Bill to take care of Lizzie, to which Bill responds coldly to him, and tells Jon he will be taking Lizzie to Sarah’s memorial.
Back at the cabin, Bill wants to know more about their baby. Lizzie tells him it was a false alarm, and that she held onto to it, because she wanted something to love so much. Bill builds his wall back up, and tells her that he doesn’t care, that he never wanted her kid anyway. She yells at him, and tells him that she knows he wanted it just as much as her, and she sees how hurt he is in his eyes. He laughs off the notion and tells her that he has no business being a parent anyway, and neither did she. She gets angry and tells him never to say that to her again. Bill says him and her are only good at one thing, and he pulls her into a kiss, tugging at her shirt. She pushed him off, and tells him she doesn’t want to, and he pulls her closer telling her getting him in bed was all she could think about before and wants to know what changed. She cries that all she can think about is Sarah, and sinks onto the couch. A frustrated Bill doesn’t comfort her, but does stay with her.
When it came out that Sarah was alive, Bill stood by Lizzie and threatened Jonathan when he attempted to take the baby back. He stayed with Lizzie to help her care for Sarah, and even accompanied her and Jon to the Bauer Cabin again to look out for Lizzie while they both spend time with the baby. Lizzie asks Bill to leave so she feel Jon out to build a custody case against him. Bill is wary, but goes anyway. Back in Springfield, Bill uncovers that Jon plans to drug Lizzie and take off with Sarah again. He heads back to the cabin where Lizzie has broke down and admitted her own custody plot to Jon, who has already drugged her drink. Bill feigns that he lost his wallet, while the three search for it, he switches the cups. Jon downs the drugged concoction, and Bill reveals the plot to Lizzie and escorts her and Sarah out.
Thinking Bill is bad for Sarah after he plots to get Jon arrested, Lizzie asks him to leave her alone. Bill is reluctant, but turns back to Ava for sex, and to forget Lizzie. Lizzie comes to Bill’s hotel room to say good-bye, as she and Jon plan to flee town with Sarah. She isn’t supposed to, but her wary attitude alerts Bill to the fact she is leaving. He tells her she’s making a mistake, and asks her to leave Jon for him. Lizzie looks convinced, but just then Ava exits the bathroom in a towel. She gets angry, and the girls almost fight, but when Ava goes back to the bathroom, Lizzie is angry with Bill. He tells her Ava is not her, and he uses Ava to try and get over her. Lizzie in unconvinced, but the two agree they could never make a relationship work even if she was staying. Despite this, just before she turns way, they share a passionate and lingering kiss.
When Lizzie and Jonathan decided to stay in Springfield, at Billy’s urging, Bill went after Lizzie. He did it in his own way though, in trying to bring down Jon and fight off Alan all on his own. He even tried to pin a murder on Jon when he found out the two are thinking of getting married for Sarah’s sake. By this point even Dinah is rooting for the pair, and urges Bill to just put everyone out of their misery and tell Lizzie he loves her. Still locking raw emotions away though, Bill refused.
The day of her wedding, Bill stops in the nail parlor when Lizzie is there. The two share a close conversation, in which Lizzie appears to want Bill to stop her from marrying Jon. Bill picks up on the bait, and genuinely asks if it were possible that he could. Just as Lizzie starts to speak, she is once again halted by the fact Bill was there to pick up a worker at the salon. She crushes the flower he gave her, and ignores him, but before he leaves, he plants a deep and dramatic kiss on her lips.
At her wedding, Lizzie gets ready to become Mrs. Randall again. Mid-ceremony, Bill bursts in and tells her she’s making a big mistake. He says Jon doesn’t love her, and that she needs to stay in Springfield, because she belongs there, and she belongs with him. When Alan comes in though, and agrees to not hurt the pair, Lizzie refuses to take Bill’s hand and leave with him. Devastated, he allows Billy to take him back to Cross Creek. Bill is on a rant about Lizzie, when she enters the cabin; un married, and declared that because of his antics, her eyes were open, and she couldn’t marry Jon. The two kiss, and Bill expressed how happy and lucky he is to have her.
Over the next few weeks, things went sour with Jonathan over Sarah, and lots of treachery and misunderstandings ensued. Things had gone sort of South with Lizzie and Bill again, but when she was forced to give up Sarah for her own safety, Bill was there to comfort her. Though she had made a deal to live with Alan for Sarah’s freedom, Bill pulled several stunts with his sister Dinah (who was/is plotting to take Alan down) and freed Lizzie from her grandfather.
Lizzie expressed doubt in trusting Bill. She feared for Sarah’s safety if she left Alan, and was afraid to commit to Bill because his continued sexual relationship with Ava. Bill promised he was done with Ava though, and that he would take care of Alan, and keep him from Sarah. The two made love in Bill’s hotel room. Afterwards, Lizzie told Bill she was afraid he would push her away again, and that she would lose him. Bill surprised her by asking her to move in with him. She accepted, and moved into his room.
Bill made good on his word, and bailed Alan out of jail in order to blackmail him away from Lizzie and Sarah. He returned to their room, and told Lizzie her home was with him now, and the pair began to make love again.
Basking in their new relatinship and living arrangements, their happiness was briefly disturbed by Lizzie finding out that since her grandfather lost the mansion over tax fraud charges, all of the things inside would be auctioned off to the highest bidder. Lizzie was devastated at the thought of her childhood heirlooms going to complete strangers, despretely clinging to the few good memories she had while growing up. Bill tried to understand, but Lizzie left to go try and retrieve them. She was side-treacked however, while in a disagreement with Ava Peralta at Ceders, she was told callously by her rival that her Uncle Gus was near death. Lizzie forgot about the auction, and went back to her and Bill's Beacon room, morosely listening to music. Playing his white knight card yet again, Bill walked in toting Lizzie's childhood dollhouse, which her father had purchsed for her when she was a child. She had explained to Bill earlier the significance of this memory item. He had purchased it for her at the auction, hoping to quell some of her sadness. Lizzie was overhwhelmed by his gesture of love, and hugged him through her tears for Gus.
Gus died from his injuries, and Bill accompanied a heartbroken Lizzie to the services. Before the funeral, in a fit of rage over Bill's choice of Lizzie over her, Ava Peralta lied telling Bill she was carrying his child. At the graveside, Bill held Lizzie as she cried over Gus, and her daughter Sarah. He questioned her about motherhood, not letting on that he may soon be a father himself. Back at their room, Lizzie expressed sorrow over being a Spaulding, and all the baggage that came with it. Depsite this Lizzie told Bill she had one good thing others didn't; him. The pair made love. As Lizzie slept, Bill gently left, covering her up and kissing her shoulder tenderly as he went. Bill found Ava, and let her know he was not going to buy her pregnancy story, he needed hard evidence. Bill found Lizzie fondly playing with her dollhouse. He tried to tell her about Ava's baby, but when she expressed how safe she felt with him, Bill was unable to continue. He kissed her, telling her she was always safe with him.
Bill forced Ava to take a pregnancy test at Towers. Ava freaked, knowing she was not pregnant, and had a pregnant bathroom attendant pee on her test for her. She showed the positive to Bill, who was forced to admit the 'truth' to Lizzie. Lizzie was crushed, but decided to support Bill the way he had supported her. After witnessing a close moment between Bill and Ava (iniatied by Ava) Lizzie left Bill stranded at a parking lot. He walked home, and instantly got a call from Ava, pretending to be freaking out and needing him. Bill didn't take the bait however, and joined Lizzie in the shower instead. As they lay on the bed post love-making, Lizzie apologized to Bill for leaving him. He accepted her apology, and told her she had nothing to worry about from Ava. Lizzie gave Bill some of Sarah's old baby clothes, for if his child is a girl.
Bill asked Lizzie to be a part of Lewis's new 'green' building project, and she accepted. As the two celebrated, Bill received another freak-out call from Ava. Bill tried to shrug her off, but Lizzie insisted he be there for her, for the child's sake. Not wanting to go himself, Bill sent Lizzie in his place. Lizzie let Ava know that she and Bill were a package deal, and would both be a part of the baby's life.
Ava's stunts to try and win Bill continued, so Lizzie paid Remy to woo Ava away from thoughts of Bill. The plan seemed to somewhat work.
Now owning the majority of the Spaulding stock, Dinah decided she wanted to merge Spaulding Enterprises with Lewis Construction. She wanted Bill to head the company. After receiving Lizzie's blessing to helm 'Spaulding-Lewis Enterprises', Bill set the plan in motion, much to his father's discontent. Bill, still having something to prove to the town, decided he would rather Lewis absorb Spaulding, destroying Lizzie's family company for the better of his own. He failed to tell Lizzie this, and in a tantrum over being kicked out of Bill's big meeting, Ava blabbed to Lizzie what she had read in Bill's email, that Bill and Dinah planned to crush her family. Ava went further by telling Lizzie that Bill had only been sleeping with her to gain insight on her family.
A heartbroken Lizzie railed against Bill for this deception, for steam rolling her family and giving her false hope about them. She told Bill that he had only been using her, while she had blindly thought he was falling in love with her. Bill told Lizzie that he does love her, but that the takeover is just business. She asked him to drop the merger so she can trust him, but he stayed silent, and Lizzie took that as his answer, and said goodbye. She moved out of the his room, and in with her Mom. She also decided to win the company back, and in a business arrangement, has teamed up with Alan to do just that.
Bill was furious at Ava for stabbing Lizzie in the heart, and making her feel he had used her. Finally seeing her manipulations first hand, Bill wrote her a check for all of her medical expenses and baby needs, and told her not to call him until the baby is being born. He then tried to woo Lizzie back by phone calls, following her to the park, and even parking under her window waiting for her to come outside. In a last ditch attempt at a romantic gesture, Bill held a boom-box blaring a love tune over his head under her window (mimicking John Cusack's gesture in the famous 80's love flick, Say Anything) Lizzie appeared affected, but still didn't budge.