Despite his protestations, the aloof and politically ambivalent Boris Grushenko (Woody Allen) is gradually drawn into the Russian army during the Napoleonic invasion of Russia, and despite his cowardly ways, he becomes a war hero. This makes him a potential partner for the lovely Sonja (Diane Keaton), who has long been the woman of his dreams, but who had never been more than a friend to him. Sonja's love had always been directed at Boris' brother Ivan. When Ivan's death in battle clears the way for romance, Sonja's doubts about whether she loves Boris ensure that her relationship with Boris develops very slowly, Bit by bit, however, they fall in love and that love continually deepens.Improbably, and as a result of Sonja's goading, Boris' pacifist philosophies evolve into activism to the point that he and Sonja plot to assassinate Napoleon (James Tolkan), but somebody else beats them to it by minutes. Unfortunately, Boris is the one discovered at the crime scene, and he is arrested and sentenced to death.While in prison, the atheist Boris is, strangely, transformed into a man of deep religious faith and he is visited by an angel that promises to save him from the firing squad. Unfortunately, his execution does take place, leaving Boris disillusioned, and at the moment of his death, his personal philosophy has settled into the realization that love and death are the true essence of the human experience, and that embracing deep religious and metaphysical philosophies, while intellectually stimulating, is an ultimately meaningless, fanciful pursuit.