After Myka leaves the warehouse, Pete gets a new partner: ATF agent Steven Jinks, who has a gift for sensing when someone is lying. Pete and Steven take on a new case in Denver, while Artie, Claudia, and Leena deal with a deadly pair of statues at Warehouse 13.
While Pete and Myka go after someone using an artifact to induce Alzheimer's, Claudia goes on her first case as a full agent with Steve to track down Typhoid Mary's knife.
Songs: Kathryn Calder -- So Easily
While Artie and Claudia meet with Vanessa Calder and Hugo Miller to investigate a computer virus that transforms people into clay, Myka and Pete wake up naked in bed and try to find a missing Steve.
Songs: Joan Jett
-- Bad Reputation, Scars on 45 -- Change My Needs
While Claudia and Steve attempt to infiltrate a Civil War reenactment to recover U.S. Grant's flask, Pete and Myka must deal with Pete's ex-wife... who has been stung by an artifact bee that has turned her into a human queen bee.
When a series of mysterious disintegration deaths occur in Pittsburgh, the team discovers that the artifact responsible, Joshua's Horn, has ties to Helena's time as an agent in 1893.
Great Lake Swimmers -- Moving Pictures, Silent Films, Bobby Day (1)
-- Rockin' Robin
Pete, Claudia, and Myka are called in to help Fargo, who is trapped in a virtual reality swords & sorcery game. Meanwhile, Artie and Steve are summoned to New York to recover an artifact... by FBI agent Sally Stukowski.
-- Where is My Mind?
While in Denver, Myka picks up the trail of the counterfeiter who killed her former partner, Sam Martino. Meanwhile, Artie, Claudia, and Steve interrogate a dog that witnessed the theft of an artifact.
Sally Stukowski and her partner make their move, attacking the Regents and using an artifact to trap them in a building and bring it down around them.
While Pete and his mother Jane try to determine the origins of their mysterious opponents, Myka and Claudia travel to Portland to stop a girl who can apparently vaporize anyone she hates with blasts of radiation.
Myka and Pete deal with a plague of zombies in Ithaca, while Claudia deals with a new romance, a prophecy of death, and a rejection from a friend.
As Sykes begins his end game, the agents discover that Helena is still alive... and teaching high school literature. Meanwhile, Jane reveals the full extent of her plan but one agent will lose their life carrying it out.
As Christmas approaches, Pete inadvertently activates an artifact that sends him to a reality where he never existed. To thwart an old enemy, Pete must gather Myka, Artie, and Claudia from their new lives and return to the warehouse to undo the artifact's effects.