Guess What's Coming to Dinner? is the ninth episode in the fourth season of the re-imagined Battlestar Galactica. It first aired on television on May 16, 2008. The title is most likely a play on the title of the 1967 film Guess Who's Coming To Dinner starring Sidney Poitier.
The episode begins moments after the conclusion of the previous episode, "Faith". The damaged Cylon basestar has arrived at the same location as the Colonial ship Demetrius. Capt. Kara "Starbuck" Thrace and Lt. Sharon "Athena" Agathon talk with Capt. Karl "Helo" Agathon, the executive officer of the Demetrius, and remind him that both ships must jump at the same time so that they arrive back at the Colonial Fleet together. If the Cylon basestar arrives alone, the Galactica will attack the damaged basestar and likely destroy it. The ships jump, but the Demetrius suffers a mechanical error which prevents it from jumping. For a few critical minutes, the Cylon basestar will be alone. The basestar arrives in the midst of the Colonial Fleet. The civilian ships jump, while the Galactica launches its fighters and prepares to fire its weapons at the Cylon vessel. Athena attempts to communicate with the Galactica, but the Cylon communication system has been damaged. Just as the Galactica is about to fire on the defenseless Cylon vessel, Col. Saul Tigh orders a halt to the attack, surprising Adm. William Adama. Just then, the Demetrius jumps into the battle, interposing itself between the Galactica and the Cylon ship. Helo communicates with the Galactica, advising the Colonial ship that the basestar is under the control of Capt. Thrace. Adama orders the attack to end.
Lt. Felix Gaeta, shot in the lower leg by Samuel Anders in the previous episode, is quickly taken into surgery aboard the Galactica. Colonial troops board and take control of the Cylon ship. Adm. Adama, President Laura Roslin, Col. Tigh, and presidential aide Tory Foster interview Natalie, one of the Sixes and leader of the rebel Cylons. She tells them of the Cylon civil war and the rebels' desire to find the Final Five Cylons, whom they believe will help them find Earth. Adama and Roslin express disbelief that the Cylon rebels can be trusted, but Natalie offers them proof of her goodwill: The "Final Five," she says, are somewhere in the human fleet. Natalie offers to take the Galactica to "the Hub." The Hub is a nexus which coordinates the operations of all Cylon "resurrection ships." If the Hub is destroyed, the resurrection ships will cease to function and all Cylons will become mortal. By helping destroy the Hub, the Cylon rebels hope to prove their worthiness to the Final Five, encourage them to reveal themselves to the rebels, and lead the way to Earth. The Colonials express disbelief that the Final Five will expose themselves. But Natalie says that the Hub is also where the deactivated Number Threes known as D'Anna Biers are located. The Cylon rebels can reactivate the Number Threes, who know the faces of the Final Five.
After some additional concessions, Roslin and Adama agree to the plan.
Meanwhile, Gaius Baltar continues to broadcast religious messages to the Fleet. In his latest sermon, Baltar accuses President Roslin of discussing her chamalla-induced religious visions with Athena and Caprica-Six (who remains imprisoned in the Galactica's brig). Lee Adama confronts Roslin and demands to know if Baltar's accusations are true. Roslin does not confirm or deny Baltar's claims, but counters by asking Lee what he would do if they were true. He is unable to say what he would do.
Roslin later meets with her aide, Tory Foster, and accuses Foster of telling Baltar about her visits with Athena and Caprica-Six. Foster denies being a spy, but does admit to having had a religious conversion to Baltar's teachings. Roslin expresses skepticism at Foster's explanation, and tells her that if she wants to keep her job she has to find out who the real spy is.
Later, Roslin, Athena and Caprica-Six once again have their shared dream in which Athena and Roslin chase Athena's half-human, half-Cylon child, Hera Agathon, through a metaphysical opera house only to have Caprica-Six take the child into a brilliantly-lit auditorium. This time, however, Gaius Baltar is seen waiting at the entrance of the brilliantly lit door, walking away with Six and Hera. When Athena awakens from her dream, she finds Hera by her bedside. Hera whispers, "Bye-bye."
Adm. Adama briefly discussed the forthcoming attack on the Hub with Col. Tigh. He asks Tigh how he knew that the Galactica should not fire on the damaged basestar, but Tigh can give no rational explanation.
Aboard the Cylon basestar, Natalie, Leoben Conoy, and the leader of the Eights discuss the plan to destroy the Hub. Natalie expresses doubt that the humans will trust the Cylons after all that has happened, and the Eight agrees. Natalie argues that the Galactica will turn on the damaged Cylon basestar after the Hub is destroyed. To prevent this, she suggests that the Cylons use the Centurions to seize the hostages. The others agree.
Lt. Gaeta's leg is amputated below the right knee, traumatizing him. When Laura Roslin goes to the Galactica sick bay for cancer treatments, she hears Gaeta singing. Starbuck visits her there, and tells Roslin that the Cylon Hybrid prophesied that "the dying leader shall know the truth of the opera house". A startled Roslin asks for Thrace's help in unraveling the meaning of her vision, and Thrace agrees to do so.
Lee Adama also visits Roslin in the sickbay. Vice President Tom Zarek has informed the Quorum of Twelve about the upcoming attack on the Hub, and the members of the Quorum are ready to support a motion of no confidence against Roslin. Lee tells Roslin that he saw the fear and purposelessness in the Quorum's eyes when the Fleet jumped to safety after the basestar's arrival. He says he now understands why Roslin has taken such a hard line with the Quorum. However, he begs Roslin to speak with the Quorum or perhaps even let Natalie talk to them. Roslin cannot win the support of the people, he argues, unless the Quorum is with her. And the Quorum won't follow her unless she gives them some reason to believe in her.
Tory Foster continues her sexual affair with Gaius Baltar, but is now emotionally distant from him. Baltar asks her what is wrong. At first, she denies anything has upset her, but then accuses Baltar of spreading lies about Roslin meeting with Athena and Caprica-Six. Baltar denies that he is spreading lies, but Foster insists that he is lying in order to manipulate him into revealing his source. Baltar reveals that it was Caprica-Six who told him about Roslin's meetings with herself and Athena, but this took place months ago during his trial for crimes against humanity.
A short time later, Roslin meets with the Quorum. She refuses to explain herself, but says she has brought a guest who will provide an explanation of why the Galactica is going to attack the Hub. Natalie is brought into the room. She tells the Quorum that the Cylon rebels have realized that death is an important part of life. The Cylons have begun to cherish every moment of the life, now that they realize they might permanently die. They no longer wish to engage in war, but need humanity's help to not only help them find Earth but also bring this realization to all Cylons everywhere. The stratagem seems to work, and Roslin gets the support of the Quorum.
Back aboard the Cylon basestar, Natalie discusses her meeting with the Quorum with Conoy and the leader of the Eights. She tells them that she was dismayed by the humans' reaction. Conoy assumes that the humans don't trust them, but Natalie says he is wrong. The humans are afraid and desperate, she says. They won't betray the rebels, but rather are counting on them to help end the war and save their lives. Natalie demands that the plan to take hostages stop. Conoy says that the Centurions already are moving to seize prisoners, and that the plan can't stop. Natalie is adamant, and Conoy tells her to return to the Galactica and stall for time while he attempts to stop the Centurions.
Aboard the Galactica, Capt. Karl Agathon and Capt. Kara Thrace arrive on the flight deck with Gaius Baltar. He is put aboard a Colonial Raptor, and is surprised to find Laura Roslin also on board. Roslin tells him that they are going to the Cylon basestar to talk to the Hybrid. Baltar asks why he is going. Roslin explains that he is in her dreams, and apparently only the Hybrid knows the meaning of her visions. Soon, the Raptor arrives aboard the basestar—where the Cylon Centurions are making ominous moves throughout the ship.
Lt. Sharon Agathon arrives home in her quarters aboard the Galactica to find her daughter, Hera, coloring in a book. When she looks at the book, it is filled with childish drawings of the Cylon Six model and the number six repeated over and over. Athena looks up to find Hera gone. She runs through the ship, trying to find her child, as visions of her running through the opera house in pursuit of Hera flash through her mind. In a corridor, Hera meets Natalie, who is being escorted by several Colonial Marines. Hera stops and Natalie kneels to greet the child. Athena rushes up and pulls a gun on Natalie. She announces that Natalie will not take her child. Athena asks Galen Tyrol, who has also arrived on the scene, to take Hera away. He does so. Natalie says she does not want the child, but Athena shoots her twice and Natalie appears to die.
Aboard the Cylon basestar, Roslin, Baltar, and the leader of the Eights arrive in the Hybrid's room. Roslin orders the Hybrid reconnected to the basestar's systems. As soon as the Hybrid wakes up, it screams "Jump!" The basestar then jumps away from the Fleet.