Jack's son, David, is shown reading an annotated version of Lewis Carroll's Alice in Wonderland (in season 4 he also read this to Aaron). Jack refers to Alice's two kittens, Kitty and Snowdrop, one black and one white. Also in this episode, Jack finds a key to his ex-wife's house hidden under a rabbit statue. Both these things refer to the fifth episode of
Season 1, entitled "
White Rabbit". In that episode, Jack chases his dead father to the caves, eventually finding
Adam and Eve, along with two stones, one white and one black, in the pocket of one of the corpses. In the flashback, Jack's father tells him he doesn't have what it takes.