1938. Julia Lambert (Annette Bening) and Michael Gosselyn (Jeremy Irons) are the royal couple of the London theater scene, Julia, an actress, and Michael, a former actor, who took over running the theater and its troupe after the death of their mentor, Jimmy Langton (Sir Michael Gambon). Jimmy is still constantly with Julia in spirit as she navigates through life. Besides their work, Julia and Michael lead largely separate lives, they, long ago having stopped a sexual relationship. Julia of late has been feeling disenchanted with her life, she not wanting to admit it's because she is approaching middle age. Her disenchantments manifests itself in wanting Michael to close their current production early so that she can recharge her juices, something he is reluctant to do if only for not wanting to let the theater sit empty. What Julia ends up doing instead is embarking on an affair with Tom Fennel (Shaun Evans), an adoring young American who is young enough to be her son. As Julia and Tom's relationship progresses, the more she falls in love with him and becomes dependent upon him for her happiness. But as she finds out that Tom is not as innocent and shy as he first made himself to seem, she may learn that Tom cannot be that direct conduit to happiness and fulfillment at this stage in her life. However, she may find an avenue through Tom that may truly re-energize her for herself.