Erica Carroll

A shapeshifter is called into action; Walter finds himself in a dangerous situation during an investigation at Massive Dynamic.

Crowley notices Dean's increasing levels of aggression, and a vengeful man named Cole captures and tortures Sam.

Sam and Dean encounter a demon who is running from Crowley, but before they can do anything, Rowena intervenes; Hannah runs into someone from her vessel's past.

Erica, Ryan and Jack go on a harrowing mission to find the legendary John May (guest star MICHAEL TRUCCO -- Battlestar Galatica) in order to rescue Georgie (recurring guest star David Richmond-Peck). Plus, Anna brings Chad aboard the Mothership to do a story on her Live Aboard Program, and Tyler confronts Erica about his mysterious past. And what of Ryan's past?

Kennex and Dorian respond to a suspicious death at a hospital where – before having a fatal cardiac arrest – a man claimed someone was trying to kill him, and inexplicably knew his exact time of death. As the investigation unfolds, a black market for vital organs is uncovered in which bio-mechanical hearts can be resold and remotely "shut off." As the team fights to find the pulse of this 2048 tech-centric crime, Dorian reconnects with a decommissioned DRN.

After a US Space Shuttle crash, one of the crew, a writer, miraculously survives. He now appears to be indestructible and has gifted insight.