"Revenge" Season 4 resulted in Emily escaping from prison to violently confront Victoria, but she was saved by her thought-to-be-dead father so that she could marry Jack and live happily ever after. This season focused on Victoria seeking revenge on the woman who had destroyed her family.
The fourth and final season of the ABC drama series focused on Victoria Grayson turning the tables on Emily Thorne and getting her own revenge for all that Victoria had suffered. After being released from the mental hospital that she had been placed in by Emily, Victoria faked her own death using her mother's body in a fire. She was later tracked down by David Clarke, who had been thought to be long dead and was the source of Emily's initial plot for revenge. Victoria did her best to set David up to kill Emily, whom he did not know was actually his daughter all grown up.
After clearing her father's name and reconciling with him, Emily learned that Victoria was still alive and tracked her down with the help of Louise Ellis, who had turned against Victoria. Emily and Victoria had their showdown, but David intervened and shot Victoria himself, knowing that he had terminal cancer and would not be incarcerated for very long. Before she died, Victoria managed to shoot Emily but didn't kill her. David Clarke was able to see his daughter marry her lover, Jack, and died peacefully. Emily and Jack literally sailed off into the sunset, but she was alarmed at the thought that the heart transplant she received after being shot might actually have belonged to her nemesis, Victoria.