Season 4 kicks off with the Warehouse Team still reeling from the shocking events of the climactic season three finale -- the loss of Agent Steve Jinks (Aaron Ashmore), Mrs. Frederic (CCH Pounder), H.G. Wells (Jaime Murray) and the destruction of the Warehouse itself. Their only hope lies in racing to the other side of the Earth to hunt down an obscure artifact, which may or may not even exist -- and if it does exist, what consequences will they face for using it?
Still reeling from the destruction of the Warehouse, the team races to the other side of the Earth in search of a powerful new artifact.
Kate Mulgrew guest stars as Pete and Myka investigate a case of mass hallucinations.
It's all hands on deck as the team tracks down artifacts from Sykes' arsenal.
As his worry about Claudia grows, Artie sends his protege into the field with Pete, while Jinks and Myka head to Louisiana to investigate several psychiatric patients who have made miraculous turnarounds. The common thread is a musician, who Myka and Jinks discover is taking others' pain in order to improve his playing, though they don't know how.
Pete and Myka investigate a hockey player who seems to be miraculously and instantly recovering from serious game injuries, while Claudia is invited to a mysterious lunch by Mrs. Frederic. Elsewhere, Artie and Steve discover someone has been stealing artifacts from inside the Warehouse. Guest stars BSG actor Mike Dopud as Hockey Player "Mike Madden."
Someone has stolen Lewis Carroll's Mirror from inside the Warehouse allowing the psychotic and murderous spirit of Alice Liddell to escape again. Our team must stop her killing spree before one of them ends up dead. Guest stars Lindsay Wagner as recurring character "Dr. Vanessa Calder."
Myka and Pete wonder if the assignment Artie sent them on - discovering the cause of rapidly growing men in South Bend, Indiana - is a red herring deterring them from his secret investigation, when one of the men starts growing right before their eyes, writhing in pain.
Pete and Myka investigate the case of people literally rusting away in a West Virginia mill town. Steve and Claudia visit his hometown in New Jersey in a bid to end his dependence on the Metronome. Artie tells Mrs. Frederic and H.G. Wells the truth about Brother Adrian and his use of the Astrolabe.
To pressure Artie into reversing the Astrolabe's effects, Brother Adrian sends deadly artifacts to Myka's pregnant sister, Pete's ex-wife and Claudia's brother. As the agents race to save their loved ones, Mrs. Frederic and Steve go to the Vatican where they discover an impossible truth about Artie and Adrian. By the end of the day, one team member lies dead in Warehouse 13.
His personality split after using the Astrolabe, Artie embarks on a scheme to release a deadly virus that could wipe out half the world's population.
With hundreds – and soon millions – of people around the world suffering from the Sweating Sickness, and Artie alive but unconscious after being stabbed with an artifact by Claudia, the Warehouse team find themselves in a greater crisis than ever.
Artie's trial before the Regents clears him of charges after Leena dies by his hand, but his own guilt may be the harshest punishment possible. Claudia is deeply worried about him, so when a ping comes up – a man buried alive in a state park in Oregon – Pete takes Claudia in order to clear her mind a little.
Pete and Myka are using a jade elephant (artifact made by Indian guru Vyasa) to absorb balls of electricity that are rocketing around the library, but when a quadruple hit comes their way, it's too much for the artifact to channel, and the charge rockets onto a nearby manuscript, launching them into the world of the story.
Two jockeys in England collapse from adrenaline overload after their long-shot horses win their races, and Artie's excuse for not going with Jinks and Claudia to investigate is that Mrs. Frederic is stopping by on some Regent business.
H.G. Wells re-enters the picture to help Pete and Myka with an artifact that's forcing confessions out of criminals. Meanwhile, the rest of the team deals with earthquakes INSIDE the Warehouse.
Pete, Myka and Jinks deal with a prison break where the Marshall assigned is Steve's ex-boyfriend. Meanwhile, Artie is struck deaf and Claudia must help him.
Nothing like the 'burbs to inspire a murderous spike, and the gated community in Marlon, Ohio, is feeling that bump when a district attorney is poisoned and falls down dead on his lawn.
The team must retrieve a horde of items that went missing during the move from Warehouse 12 -- but that means teaming up the villainous Charlotte Dupres. Meanwhile, Charlotte's son manipulates Claudia. Guests: Polly Walker, Anthony Head and Josh Blaylock.
With Claudia encased in bronze and the bronzer broken (courtesy of the recently revived Paracelsus), the team is working overtime to find out where he is. In place of the artifact (called a stele) that makes the bronzer work, Paracelsus left a cryptic note: "Sutton knows what I want."
The team races to stop Paracelsus, Steve discovers Artie has been keeping a huge secret from Claudia, and Myka struggles with news of a medical condition.