BODY OF PROOF - "Fallen Angel" - Kate meets Sergei (Ivan Sergei), a handsome and mysterious guest at a political event, and is irresistibly drawn to him. But when a young Russian girl is found murdered near the hotel where she and Sergei are having a tryst, Kate begins to suspect that he may be involved and turns to Megan for help, on "Body of Proof," TUESDAY, MARCH 26 (10:01-11:00 p.m., ET) on ABC. (ABC/RICHARD FOREMAN) JERI RYAN, MARK VALLEY, ELYES GABEL, RICHARD BURGI, IVAN SERGEI