All hands are on deck looking for Claire. The durational spectrometer tells them that it was Benedict Valda - the nasty one from the alternate timeline, not the dead one from this timeline - who took her. They learn that he was camping out in the Dead Regents sector, right under their noses ever since they defeated Paracelsus. Valda slipped back through the wormhole with them thanks to an errant Versailles fork, just in case you were wondering!
When Pete and Myka respond to a ping in Rapid City and see an entire park full of people in comas, they know Valda has been there - and if they needed further proof, there is the record player that kept Claire in a coma, playing a record that blasts anyone who tries to stop it with a sonic boom. Claudia arrives with Charles Atlas' exercise trunks, Myka dons them and, with her new gravitational mass, is able to get close enough to the record player to stop the madness.
One crisis averted, Artie calls with another, bigger crisis - Valda has plans to use three linked artifacts to move the Warehouse to China, where it will become Warehouse 14. He already has one piece of the triumvirate, so to stop the progress, Myka, Pete, and Claudia must reach a spot in Boston where an artifact (half of an ancient hammer) is hidden. But when they arrive, Valda is using a mind control artifact on the now-awake Claire and orders her to move a wall aside. He darts in and grabs the artifact, but doesn't leave before he has Claire almost flatten Claudia with the chunk of wall. Claude sees her sister fight Valda's commands, but she can't free her.
At the Warehouse, Artie and Jinks try to stop the rotation of part two of three of Valda's evil plan (an ancient compass and wheel) while the other agents go to China via the portal in the Warehouse. They know that their only salvation is to stop Valda from striking the hammer against the cornerstone of the new building, but they've got to get through Claire, first. The twisted sister, via Valda's mind control orders, has them pinned against a wall in excruciating pain. As a last ray of hope, Claudia starts singing the song the two of them sang on the one day Claire was awake. Claire hears the notes and sings along, breaking the link between herself and the Regent Gone Wild.
Claudia has a crazy notion - what if they switch the direction of the mind control artifact so that the energy goes from Claire to Valda? Pete likes the idea - if they time it right, he can grab the Versailles fork from the baddie, Claire will transfer the energy, Pete will bag the fork and poof! No more volcano fire anger energy, and no more Valda. Myka and Pete work their partner magic, as they do, and Valda disappears into the ether. The artifacts that were transferring from the U.S. to China also vanish - but not into the ether. They just move from China back to their home in dear old Warehouse 13.
Claire is back, and that's wonderful news, but Pete is disturbed by this strange feeling in his chest. Heartburn? No, not that. He consults Jinksie to see if it's a lie - is he, Pete, in love with Myka? Why, yes. Yes, he is. Ruh-roh.
Myka's mind is occupied with other things, however, like why the compass and wheel that she and Artie just restored is still glowing as if activated. It's a sign of trouble that frightens even Mrs. Frederic, and they know they're in for another big fight.