There's Always A Downside Hugo resurfaces to help track down an artifact at his nephew's prep school. Meanwhile, another artifact threatens the life of a musician in New Orleans.
No Pain, No Gain A hockey player's amazing recuperative ability prompts an investigation. Meanwhile, thefts from inside the warehouse are probed.
Fractures The murderous spirit of Alice Liddell escapes after Lewis Carroll's mirror is stolen from the warehouse.
Endless Wonder Pete and Myka face a curious executive from a drug company as they deal with a pill that may increase people's height. Meanwhile, Artie, Steve and Claudia follow Brother Adrian to the place where he's hiding.
Second Chance Pete and Myka uncover people who are rusting away in West Virginia. Meanwhile, Steve tries to quit his dependence on the Metronome by visiting his hometown; and Artie reveals the truth about Brother Adrian to Mrs. Frederic and H.G. Wells.
The Ones You Love Brother Adrian resorts to extreme measures, sending deadly artifacts to the agents' loved ones, to coerce Artie into reversing the Astrolabe's effects. Meanwhile, Mrs. Frederic and Steve uncover something shocking during a trip to the Vatican.
We All Fall Down The team find themselves battling one of their own when Artie's obsession with the Astrolabe reaches dangerous proportions.
The Living And The Dead The entire planet is in danger from the sweating sickness released by Artie, who lies close to death after being stabbed by Claudia. To find a cure and save the world, Pete and Myka must rely on a seemingly unreliable professor. At the same time, Claudia and Steve risk their lives to help Artie.
Parks And Rehabilitation Artie has a few hurdles to overcome before he can get back to work; Pete and Claudia team up on a murder investigation involving a radical environmental group.
The Big Snag A mostly black-and-white episode pays tribute to film noir as Pete and Myka find themselves transported into an unfinished 1940s crime thriller. Meanwhile, Artie, Claudia and Steve chase down a phantom car thief.
The Sky's The Limit Pete and Myka head to Las Vegas to solve a series of murders surrounding the world of magic; Claudia and Jinks search for an artifact used to rig horse races; Artie is thrown for a loop by the new bed-and-breakfast manager.
Instinct H.G. Wells returns to help Pete and Myka track down an artifact that forces confessions out of criminals.
Runaway Pete, Myka and Steve team up with a U.S. Marshal to recapture two inmates who escaped from a prison in Arkansas during a volcanic event.
What Matters Most Myka and Pete investigate the effect of a mysterious artifact on the residents of a posh gated community.
Lost & Found The team set out to recover artifacts stolen from Warehouse 12 by an infamous pirate.
All The Time In The World The clock is ticking to track down an evil alchemist who has bronzed Claudia and stolen the only artifact that can reverse the condition, which seems to be affecting Mrs. Frederic and the Warehouse, too.
The Truth Hurts The team must capture Paracelsus before he achieves immortality, or worse. At the same time, Myka seems to be losing her battle against cancer; and Steve learns that Artie has been keeping life-changing information under wraps.