Official Description from the CW

SAM AND DEAN FACE OFF AGAINST LUCIFER Sam (Jared Padalecki), Dean (Jensen Ackles) and Castiel (Misha Collins) track down the Colt and head off to find Lucifer (guest star Mark Pelligreno) to send him back to Hell. It's a hunters' reunion when the crew joins forces with Bobby (Jim Beaver), Ellen (guest star Samantha Ferris) and Jo (guest star Alona Tal) for what could be their last night on Earth.

Phil Sgriccia directed the episode written by Ben Edlund.