likely refers to the "Military Police Corps" (or just "Military Police") as mentioned in Yellowjackets Season 2, Episode 5 ("Two Truths and a Lie").
It's a fact. You have six hours to leave New Jersey. Leave the files. Leave the tapes. If you don't... I won't arrest you. I'll just make you disappear. No handcuffs. No paperwork. Just... gone. yellowjackets s02e05 mpc
Who are you?