Is she, though? I feel like this is just another misdirection.
SpoilerMy money is on Agent Garrett. Why? Three reasons.
1) He went along with the plan to raid the Guest House with nary a word of protest.
2) He was Ward's CO and would know exactly what buttons to push to make Ward shoot the fake Clairovoyant.
3) Dethlok, who is just about indestructible, gave up a little too easily when ambushing Garrett.
It's a shame that he's evil, because I genuinely like Agent Garrett.