In Agents of SHIELD s03e08, Gideon Malick knows that
Simmons went through the monolith portal, and returned with the help of SHIELD.
Malick follows up in s03e09, when he
Kidnaps Fitz and Simmons, and interrogates them to learn how Simmons got back.
But how would he know that she had done this?
There don't seem to be any HYDRA spies or surveillance within SHIELD. Nobody from SHIELD has been advertising her return. Simmons has barely left the base. But Malick must know somehow – so what have I missed?