Christian Slater returns to complete his two-episode turn as a mathematician forced into Sloane and Irina's service.
For weeks, Syd (Jennifer Garner) and the CIA have been searching for the abducted brainiac with no luck. Their big break comes when his wife (Tracy Middendorf) reveals a shocker that strikes a nerve in Jack and sends Syd to Russia against her father's orders. Back in the States, a grieving Sloane deploys the newly evil Francie (or whoever she is) to uncover---and assassinate---the person responsible for Emily's death. However, the hit hits a snag that changes one agent's life forever. Diane: Yvonne Farrow. Sark: David Anders.