As Ming gets ready to proceed with her plans for artificial insemination, her husband Chen, is stressed and fantasizing about street races and infidelity. The sperm donor, Fitz, their medical school classmate and Ming's former boyfriend, is considering reinstatement at the hospital which stirs up a lot of unresolved issues. His return would also create more tension between the trio since he wouldn't be an absentee donor after all, but working alongside the couple every day.

The present. Jealous and sensing ulterior motives in Fitz's return to Toronto, Chen confronts him with a stash of love letters he wrote to Ming. The two come to blows then reflect back on a time during their residency when they helped each other out during a Code Blue. At the ensuring peer assessment review, Fitz takes stock of his mettle as a doctor, his motives as a friend and his true feelings for Ming.

As Fitz and Ming debate the merits of their insemination plans, the doctors revisit their past entanglements. Fitz finds himself challenged by the demands of a psychotic patient. Chen is called away to Brisbane to visit his dying grandfather. And Ming comes to terms with her surprise pregnancy and what it means for her future.

It's Christmas Eve, and chaos reigns in the emergency room. Fitz contends with some hard-assed cops and a belligerent patient. It's a contentious situation that he initially handles well, but as the evening progresses he spirals out of control to a very self-destructive place. When Chen finds himself dealing with a family of a man who died in a brothel, he starts to question his own views on medicine and family. Meanwhile, though she's not embroiled in the turmoil of the hospital, Ming is confronted by her father's strange solution to her fertility problems.