"Ab Aeterno" is the ninth television episode of the American Broadcasting Company's sixth season of the serial drama television series Lost and 112th episode overall. The episode aired on March 23, 2010.
In an extended flashback, after the death of his wife, Richard Alpert (Nestor Carbonell) arrives on the island as a slave on the Black Rock in the 19th century. He then encounters the Man in Black (Titus Welliver) and Jacob (Mark Pellegrino), both of whom offer him different deals in exchange for his allegiance.
The title is Latin for "from eternity", a phrase used to mean "since the beginning" or "for long ages" (very loosely translated as "your life now will be either heaven or hell throughout eternity"); this references the agelessness granted to Richard by Jacob as a reward for his service. "Ab Aeterno" was watched by 9 million American viewers and received critical acclaim by critics and audiences alike.
Plot
Prior to her arrival on the island in 2007, Ilana (Zuleikha Robinson) is visited by Jacob in a Russian hospital, where he tells her to protect his remaining candidates (continuing from her flashback in "The Incident"). Following the events of "Dr. Linus", Ilana explains to the survivors that Jack Shephard (Matthew Fox), Sun Kwon (Yunjin Kim) and Hugo "Hurley" Reyes (Jorge Garcia) are candidates to replace Jacob, the man in charge of the island, who was recently murdered by Ben. When asked what to do next, she says that Richard Alpert (Nestor Carbonell) knows. Richard, who has become suicidal since Jacob's death, says he does not know and leaves the camp.
Richard Alpert's origins begin in 1867; Alpert, known as Ricardo, lives in Tenerife with his dying wife, Isabella (Mirelly Taylor). He travels to a doctor to get medicine, but the doctor refuses Ricardo's meager payment, and Ricardo accidentally kills the man when they struggle. Ricardo returns home to find his wife dead, and he is arrested for murdering the doctor. In prison, he is visited by a priest (Juan Carlos Cantu), who states he cannot be forgiven and will be hanged. However, learning that Ricardo has been learning English, the priest allows Ricardo to be taken as a slave to the New World aboard the Black Rock. En route, the ship is caught in a storm and a tsunami sweeps it onto the Island; it crashes through the statue of Taweret, while the Black Rock runs aground into the jungle.
The next day, the crew members begin executing the captives, but the smoke monster saves Ricardo's life by killing the workers, though leaving Ricardo chained. As he works to free himself, a vision of his wife tells him they are in Hell. She is then apparently killed by the Monster. After six grueling days, the Man in Black appears and frees Ricardo. Revealing that he is the black smoke, he claims that Jacob is the devil, and that Ricardo must kill Jacob to leave the island and get his wife back. Ricardo attempts to kill Jacob, but is easily outmaneuvered.
Jacob explains the function of the island, using a wine bottle as an analogy: the island acts as a cork that keeps "the darkness" from escaping and spreading. The Man in Black finds people are inherently evil, while Jacob believes they are inherently good. To this end, Jacob brings people to the island, so they may disprove the Man in Black; however, he does not believe in telling people what to do, since this would negate their free will. When Ricardo points out that the Man in Black can corrupt others, with himself as an example, Jacob suggests Ricardo become his representative. He offers to reward Ricardo with anything he wants in return. After Jacob admits he cannot bring Isabella back or absolve Ricardo of his sins, Ricardo asks to live forever so that he never has to go to hell- something that Jacob can grant him. Ricardo returns to the Man in Black, who states that his offer will always be open. He gives Ricardo the cross necklace that Isabella gave him just before she died, and Ricardo buries it on the island.
Back to 2007, Richard visits the site where he has buried his wife's necklace, shouting that he has changed his mind and wishes to join the Man in Black. Instead, Hurley arrives and communicates with the dead Isabella, acting as an intermediary between Richard and his wife. She explains that Richard must stop the Man in Black from leaving the island, or else "we all go to Hell." The Man in Black, in the form of John Locke (Terry O'Quinn), watches them from a distance.