Artie comes in to the B&B, all a-flutter with news of a big find: crates full of artifacts that were stolen by pirate Roaring Dan Seevy. He, Pete and Myka go to Buffalo, where they discover that the key to reaching the artifacts lies with Charlotte Dupres, Sutton's "rival" (whatever that means). Pete and Myka are against any deal that has to do with her, but Artie is intent on finding the goods and convinces them that keeping her close is the safest option. After linking together their respective halves of Roaring Dan's puzzle box, they follow coordinates, locked inside, to a graveyard. There, Artie discovers another clue that points to the Niagara Falls Power Company, but Charlotte, who overheard Artie's machinations to get rid of her, fells them all with a tazer and heads to the power plant.
By the time they catch up with her, her bodyguard, Lars, lies dead, and she claims that an enormous ghost made of smoke killed him. This is corroborated by the fact that the ghost tries to kill Artie after he brushes some gold coins off a chest. They agree to work with Charlotte once again, but when she texts someone in the middle of the treasure trove, Artie knows something's up. She insists she's only after the treasure, and grabs a piece of it, summoning the ghost to strike again. The agents try to save her, but they can't dissuade the spirit. They discover it's Dan Seevy's ghost, astral-projected with an artifact. Their plan to bag it is thwarted again, and Charlotte rises from the dead and saves them.
As she explains, she's not just Charlotte Dupres, she's also the Countess of St. Germaine, aka Sutton's wife. She's been searching for the stone that can take away their immortality for almost all of the 500 years that she, her husband, and their son, have had it. She found half of it – where the other half is, no one yet knows. But the stone was only part of her plan: her son, Nick, infiltrated the Warehouse in order to de-bronze the man who cast this everlasting spell on them, a man named Paracelsus. Nick used Franz Mesmer's magnets to fool Claudia and Jinks into living in separate hallucinations that would allow him to access and release Paracelsus – for that, he had to make Claudia act out very specific instructions, including overriding Artie's DNA lock on the bronzer.
The talk of wanting to rid yourself of immortality is too much for Myka. She breaks down, and Pete rushes to comfort her, insisting he let her in. She finally tells him the truth – that she has cancer – and he promises her that he'll be there for her.
Just then, Jinks calls and frantically informs them that Charlotte's half-stone wasn't the only part of the plan that went awry: both Paracelsus and Nick are gone, the bronzer is broken, and Claudia is bronzed.
Joanne & Eddie finish up their last interview as a Warehouse 13 cast and give a shout out to all you loyal fans!
On a rainy day at the Warehouse, Pete accidentally triggers an artifact that transforms the team into two-dimensional diorama versions of themselves, and returns the Warehouse to its original, unstable design.
Who knew Claudia had those moves?! OK, so maybe they're artifact-induced, but we're so in love with the spangles, we don't care!