Well-respected stage actor Paul (Paul Giamatti) seems to be breakdown while doing a ponderous version of a Chekhov play. When he discovers a strange business dealing in soul enhancement, he is ready to trade his soul for some comic relief. Alas, giving up his soul tends to dilute his performance on stage, and he decides to rent the soul of a Russian poet to help him perform difficult Chekhov roles from Dr. Flintstein (David Strathairn). Unfortunately the transformation ruins his marriage to Claire (Emily Watson) and sends him on a journey to Russia to deal with the mob with the assistance of Nina (Dina Korzun) in order to reclaim his own American soul.