The BAU is about to expand again — and, naturally, Garcia (Kirsten Vangsness) is a little uneasy about it.

Damon Gupton joins Criminal Minds Wednesday as Special Agent Stephen Walker, whom Prentiss' (Paget Brewster) met on a case for Interpol and who is now her first hire as unit chief. As you can see in our exclusive sneak peek, Prentiss is not spilling the deets on Walker yet so as not to jinx his acceptance — but that, of course, doesn't stop Garcia from freaking out.

"Does anyone know when Agent Fill-in-the-Blank is going to start? Because I cannot start my detailed, rumor-based background check without a name," she asks JJ (A.J. Cook), Reid (Matthew Gray Gubler) and Alvez (Adam Rodriguez) in the bullpen.

Don't expect Garcia to be frosty toward Walker like she was with Alvez though. She suggests a new team nickname that is... well, not great. C'mon, baby girl, we expect more from someone who came up with "statuesque god of chocolate sculpted thunder."

Criminal Minds airs Wednesdays at 9/8c on CBS.

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