The characters of Rose Henderson (L. Scott Caldwell) and Bernard Nadler (Sam Anderson) are featured in the episode's flashbacks.
Rose, without giving an answer, reveals she is terminally ill with cancer, and has a year left to live, perhaps slightly longer.
However, Bernard succeeds in persuading Rose to talk to Isaac, who states that his office is on top of a place of great energy, perhaps magnetic or geological.
Rose Henderson and Bernard Nadler are bickering over the recent arrival of DHARMA Initiative food drops.
Jack approaches James "Sawyer" Ford (Josh Holloway) and Kate Austen (Evangeline Lilly) to explain his plan for a prisoner exchange.
Bernard enlists Hugo "Hurley" Reyes (Jorge Garcia) to gather the survivors for an impromptu meeting.
Bernard asks Charlie Pace (Dominic Monaghan) and Mr. Eko (Adewale Akinnuoye-Agbaje) to help build his S.O.S.
Meanwhile, John Locke (Terry O'Quinn) attempts to remember and to draw the writing he saw on the blast doors in "Lockdown", but to no avail.
Jack Shephard (Matthew Fox) enters the armory to change Henry Gale's (Michael Emerson) bandages and to interrogate him.
Kate notices a doll on the ground and reaches to pick it up, despite Jack's frantic cries to stop.
They determine the trap is Danielle Rousseau's (Mira Furlan) due to its lower level of sophistication and attempt to free themselves.
In the initial plans for the series, Jack was going to die midway through the first episode, and then Kate would emerge as the leader of the survivors.
[4] Kate's backstory was that her husband went to the bathroom shortly before the plane split in mid-air, and on the Island she would remain adamant that he was alive.
[4] However the producers quickly changed their minds about Jack's death, making him the leader and creating a new backstory for Kate.
[7] As Rose and Bernard are the most prominent of these characters, and fans were keen to learn their backstory, they decided to do an episode focussing on the couple.
because it showed "two characters' back stories which we've all been longing to see", comparing their relationship to that of Jack and Kate (Evangeline Lilly), and finding Rose's meeting with Isaac "particularly interesting".
[12] Lost producer Leonard Dick called Rose and Bernard "much-beloved characters", and thought they did an "excellent job" in "S.O.S.".