Supernatural (TV series)/Recap/S04/E21 When the Levee Breaks

Season 4, Episode 21:

When The Levee Breaks
Dean and Bobby lock Sam in Bobby’s panic room so he can detox from the demon blood. However, as Bobby sees more seals are being broken he tells Dean they should let Sam out to help them fight the impending Apocalypse. Dean disagrees and goes to Castiel for help. Dean confronts Castiel, who says he should serve God in order to save Sam. Dean accepts. Meanwhile, Sam escaped from the panic room (with Castiel's help) and has met up with Ruby. After giving Sam a dose of her blood, Ruby reveals the reason she's been incognito for the past few weeks. She has been tracking down Lilith, and has found one who she calls Lilith's "personal chef". Cut to two nurses in a maternity ward discussing another nurse who stole two babies. One of the nurses' eyes turn black, and she remarks that the babies look delicious, answering the question of what Lilith eats. Later, Dean tracks Sam to the motel he is staying at. Sam and Dean have a blowout confrontation.

Tropes

 * Eats Babies: Lilith
 * Ironic Echo: Dean's last lines to Sam in the episode are just like what John said to Sam before the latter left for college.