Sykes reveals his plan to get revenge on the Regents and recover the Collodi Bracelet, a plan that will cost one agent their life.
Pete inadvertently activates an artifact that creates an alternate reality where he never existed. To restore reality as he knows it, Pete must track down his friends, who have new lives and no memory of him.
While Brother Adrian ramps up his campaign against Artie by targeting the team's loved ones, Steve and Mrs. Frederic discover the reason behind the Brotherhood's attacks.
Pete tries to adjust to a new partner while investigating a string of bizarre deaths in Denver. The last words of the victims leads the agents to an old friend. Meanwhile, Artie and Claudia try to stop a lightning storm in the Warehouse.
A mystery organization launches an attack on the Warehouse Regents, trapping them in a skyscraper. While Myka and Artie try to get them to safety, Pete and Claudia try to find the artifact responsible.
After discovering the truth about their situation, the agents gather at the warehouse and set out to find the person responsible for the warehouse thefts and the attacks on their loved ones... before the responsible party endangers the world.
The agents capture Paracelsus, but soon discover that's exactly what he wants. Meanwhile, Myka goes in for surgery and Artie tells Claudia a family secret.
Fighting off the symptoms of the Black Orchid artifact, the team rushes to undo the Sweating Sickness that Artie unleashes in a worldwide pandemic.
With the destruction of Warehouse 13 and the death of three of their friends, the only hope left for Myka, Pete, Claudia, and Artie is to recover an obscure artifact which may not even exist... and which could have deadly consequences when they use it for personal gain.
H.G. calls the agents when she needs help with an artifact. Meanwhile, a series of mysterious quakes shake the warehouse.
After bronzing Claudia, Paracelsus escapes with the only artifact that can cure her, and the team has to hunt him down before it's too late. Meanwhile, Claudia's link to Warehouse 13 endangers the building and Mrs. Frederic.
Steve, Artie, and Claudia take try to find where Brother Adrian has been hiding. Meanwhile, a powerful company executive may have created a new artifact-related drug with the ability to increase people's height, and Myka and Pete must try and stop it.
Pete helps Myka catch a dangerous killer--the man who murdered her previous partner. Meanwhile, Artie, Claudia, and Steve interrogate a dog that is a key witness to the theft of an artifact.
While Myka and Pete deal with a zombie plague spread by an unknown artifact, Claudia tries to reach Jinks.
While Artie and Steve investigate the theft of artifacts from the warehouse, Mrs. Frederic invites Claudia to lunch and Pete and Myka investigate a miraculously-healed athlete.
Pete and Myka require the rest of the team when they have to track down the remaining artifacts from Sykes' arsenal.
The team gets news that will affect their future - and that of the Warehouse - forever.
Pete and Myka are hot on the historical trail of pirate Roaring Dan Seavey, who engineered the theft of artifacts from Warehouse 12.
An artifact sucks Pete and Myka into a 1940s detective novel, but their lives are in real danger. Meanwhile, Artie, Steve, and Claudia go after a phantom car thief.
An artifact from a previous case, Lewis Carroll's mirror, turns up missing from storage and the team set out to recover it.
The agents investigate when a series of mysterious incidents occur at an expensive gated community, and soon discover that someone is using an artifact to get revenge.
Paracelsus takes control of Warehouse 13 and uses his newfound abilities to terrorize the team... and then travel back in time to create an new timeline where he rules the warehouse.
An old enemy returns and attempts to move the Warehouse - and plans to use Claudia's sister to do it.
While Claudia and Myka investigate the case of a woman who can disintegrate anyone who angers her, Pete and his mother deal with their issues after being reunited.
While Artie tries to get back to work, Pete and Claudia investigate an environmental group that may be tied to an artifact... and a murder.
The Warehouse agents go after an artifact that causes persons to hallucinate and riot.
Pete and Steve search for a dangerous artifact at a Renaissance fair, while Claudia takes a risk to revive her sister from a coma.
The team get word that an artifact is at the prep school where Hugo Miller's nephew attends. While Pete and Claudia check out the prep school, Myka and Steve track down another artifact in New Orleans.
Pete, Myka, and Steve team up with a U.S. Marshal to track down two prisoners who escaped prison during a volcanic eruption.
While Pete and Myka try to track down an artifact that causes people to rust to death, Steve and Claudia try to find a way to cut him off from the metronome artifact that is keeping him alive.
While Pete and Myka investigate drowning incidents on dry land, Artie and Claudia try to find out more about Claudia's sister.
While Pete and Myka travel to Las Vegas to investigate a series of deaths involving falls from great heights, Claudia and Steve become involved in horse racing. Meanwhile, Artie tries to cope with the B&B's new manager.
The agents and Claudia team up to free Douglas Fargo and another gamer from a virtual reality fantasy world. Meanwhile, Steve and Artie try to steal an artifact painting in New York but run up against FBI agent Sally Stukowski.
Pete, Myka, and Artie are sucked into a Telenovela while helping Pete's ex-girlfriend track down an artifact.