RR continues to be wild card - are he & Mueller leading the sting or its first targets ... TBD ;)
Rosenstein did report that he would recuse himself as Acting Attorney General once Muller started looking at FISA process, since his (Rosenstein) name was on one of the three FBI applications, to the FISA court.
That tells me Muller must not be yet even nosing into a FISA investigation. Rosenstein has indicated a recusal if he is called as a witness.
The outside prosecutor whom Rosenstein/Sessions appointed may be the one working on the FISA shenanigans, perhaps a long side of the Inspector General at the FBI.