As with comic book superheroes, death is often a revolving door for the Winchesters, but this issue is confronted head on in Red Meat.
Kicking off in media res, with a tussle with some werewolves going south when Sam gets shot, the story then unfolds with a few flashbacks explaining how the Winchester brothers ended up in a cabin in the middle of nowhere, rescuing a couple of hikers - Michelle (Alphas' Erin Way) and Corbin (Blair Penner) - from the werewolves.
Realising there are more werewolves out there, they all then try and make it back to civilization, but critically-wounded Sam is slowing them down and so, while Dean is away, Corbin suffocates Sam!
Eventually, the three survivors turn up in hospital, but Dean decides he's going to try and cut a deal with Billie (Lisa Berry) The Reaper to bring Sam back to fight The Darkness.
However, after he swallows a fistful of pills, Billie tells him that she is adamant that the Winchesters won't be getting any more 'second chances' and that Sam isn't dead anyway.
Having woken up, Sam finds a couple of werewolves between him and telling Dean that Corbin is sporting an infected bite mark.
Red Meat is a thematically dark episode, and although, in a sense, it covers old ground (e.g. Billie's determination that the Winchesters have used up all their Get Out Of Death Free cards), it does it very succinctly, emphasising Dean's need to have his brother around over his determination to avert the latest apocalypse.
Robert Berens and Andrew Dabb's script also addresses the trauma endured by survivors, those civilians drawn in to the Winchesters' world who lose loved ones to the forces of darkness and then have to carry on with their lives.
While not directly a part of the main season arc - although it is referenced - this isn't an episode you should skip.