Just how dangerous is it to house thousands of powerful artifacts in a single building? Last night's episode of Warehouse 13 answers that question with a visit to the Dark Vault, Sylvia Plath's depression-inducing typewriter, and homicidal, autonomous dodgeballs.

The last few episodes have me convinced that Warehouse 13 is really hitting its stride, and "Breakdown" was perhaps the best yet, with the writers really getting a chance to spread their wings and play with the characters, artifacts, and the Warehouse's mythology.

We had two major plotlines running through this episode. The main plotline centers around Pete, Myka, and Claudia handling a major snag in the machinery that neutralizes the artifacts, causing several of the artifacts to activate at once and threatening to destroy the Warehouse. The second involves Artie's coming to Jesus moment with the shadowy Regents behind the Warehouse.

Earlier in the season, I could have seen the Warehouse's artifacts getting old quickly, but they're actually taking on an increasing charm. Earlier artifacts, like hypnotherapist's James Braid's chair, sometimes felt a bit random, but the latest round of artifacts have a clear logic of their own. After years of school systems trying to convince us that dodge balls are evil, we get actual killer dodge balls, which can only be defeated by being caught. And the mystical replica of Leena's bed and breakfast, which can only be manipulated through the the painting on the wall had a gratifying video game feel to it (Could I please have a Flash game based on Warehouse 13? Maybe something in the vein of the Mystery of Time and Space, but with artifact-based puzzles?). And there's the wonderfully freaky suggestion that the Dark Vault, which we got to peek inside last night, is filled with trapped souls and demonic beings — how long before that evil clown comes out to play? And there was a nice shakeup in pairing Claudia with Pete and Myka for the whole episode, really cementing what was once an odd-couple cop show into an ensemble dramedy.

Artie, meanwhile, gets ambushed by the Regents, who demand that he justify his operations at the Warehouse. It's obviously a talkie bit of scenes, nicely handled by Mark Shepherd — who has become science fiction television's "must have" guest star — and they add a bit more to the Warehouse 13 universe. In some ways, they feel like a less snooty version of the Watcher's Council from Buffy the Vampire Slayer, ready to appear at any moment and take the Warehouse staff to task, and I imagine we might see them later, with Artie forced to defend one or more of his crew to them. But even if they look like waiters, retirees, and business folk instead of shadowy figures, there's a very mysterious quality to them. Are they as ordinary as they claim? What is this higher power that they serve? And why do they feel so threatened by Artie's ex-partner-turned-rogue-artifact-hunter James MacPhereson?

We'll find out the answers to that last question at least, soon enough, as we're rolling along toward the season's end. But not before next week's episode, when Saul Tigh himself, Michael Hogan, guest stars as Myka's father in an Edgar Allan Poe-themed mystery.