After sunset on Christmas Eve, Mac has a car wreck, which renders her unconscious and sends her to a hospital; she dreams flashbacks about a recent conversation with her therapist and about certain significant events in her life, especially ones involving Webb and Harm. While unconscious Mac repeatedly speaks Harm's name, so an EMT finds Harm's cellphone number in Mac's PDA, then the EMT calls Harm. Harm promptly goes to Mac's hospital room, and he soon says that he'll stay there with her that night. Harm and Mac start a process of reaching out to and communicating with each other.
—DocRushing