A MacPherson-focused Artie has Pete, Myka and Claudia on inventory duty, but a moment of teasing between Myka and Pete turns into a explosion of light as the Studio 54 disco ball tumbles down and Lewis Carroll's mirror topples. Artie decides it's time to assign them a case, so Pete and Myka are dispatched to Las Vegas. Pete can't wait to play the high roller...but what is it that seems different about Myka?
Back in the Warehouse, Artie and Claudia return everything to its proper place but when they lift the mirror, they don't see their reflections; they see Myka, screaming silently, desperately trying to free herself.
Pete and "Myka" find Gary and Jillian, a sexy couple with a healthy pile of chips on the table. Gary looks unwell, and Pete decides to toss their room while "Myka" continues surveillance. She notices a chip of a different color behind Gary's stack and that his right hand is blistered but, when Pete later asks if anything has caught her eye, she lies.
Meanwhile, at the Warehouse, Claudia is pulling files with references to Alice Liddell, Charles Dodgson and Lewis Carroll (Dodgson's pen name). Dodgson was documenting a young woman's descent into madness and his stories were, in reality, Warehouse fabrications to hide the truth. Warehouse field agents reported that they trapped Alice Liddell inside the mirror, somehow. Leena asks about artifact interaction: "Could reflections switch places? Could people?" Artie realizes with horror that Myka is trapped in the mirror.
Back at the casino, Gary grows sicker. Pete shadows Jillian, noticing her blistered fingers and glimpsing the well-worn chip. "Myka" stays on Gary, who, once she smashes him in the face, is sorry he answered the door. Downstairs, Pete convinces Jillian to surrender the chip to him. As his fingers close around it, he sees into the future! Pete is stunned, but he bags it and suggests the Whitmans find a beach far away.
In the Whitman's room, "Myka" blasts Gary with the Tesla before leaving. She's surprised to see Pete as she opens the door, but he's even more surprised at the scene inside, and pulls his gun. She explains she has no intention of returning to the mirror and, as Pete tries to cuff her, incapacitates him with the Tesla.
The effects of the chip are evident as "Myka" arrives at the Warehouse. Sledgehammer in one hand, gun in the other, she approaches the tarp-covered mirror. Myka's reflection looks back in fear as "Myka" tears down the tarp, hammer raised. A pelting of ping-pong balls distracts the doppleganger - Pete's practice pays off - and she levels her gun at Pete. Before she can pull the trigger, Artie fires a flare as Leena activates the Studio 54 disco ball.
Shafts of light hit "Myka," twisting around her body. Screaming, she's drawn back into the mirror, which shudders violently, falling forward. Pete and Artie rush to lift it off the floor, revealing a monstrous Alice...but what about Myka? Another blast of light delivers Myka back to them. From inside the mirror, Alice vows revenge, but Pete quickly pulls the tarp down - this mirror is destined for the Dark Vault.
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!