Michael Cohen, once former President Trump’s personal attorney and fixer, has come face-to-face once again with his former client in a Manhattan courtroom.

Cohen, taking the stand in Trump’s hush money case Monday, is the prosecution’s star witness in a case that charges Trump with falsifying 34 business records over a $130,000 hush money payment Cohen sent to a porn actor to keep her quiet about an alleged affair with the then-2016 candidate.

Cohen and Trump have since ferociously turned on each other, making Cohen’s testimony — the second time he’s taken the stand in a Trump case — particularly volatile.