Based on the novel by Christopher Isherwood, "A Single Man" chronicles a day in the life of George (Colin Firth), a British professor teaching in Los Angeles in 1962.

Not just any day — by most outward appearances, George seems to soldier on, tending to his routine. But he is still devastated by the sudden death of his longtime partner, Jim (Matthew Goode).

Through flashbacks we learn of George's love for Jim (and vice versa) — in these scenes, we see George as the older man, completely devoted yet amusingly caustic about their relationship.

George's life changes as the result of a snowy night up north, a car accident, a phone call from a relative, the bitter reminder that he is not considered by Jim's family to be an essential enough part of his longtime partner's life to attend the funeral.

George has chosen this particular day, it seems, to join Jim. We follow him as he puts his affairs in order, cleaning out his desk at the university, visiting the bank to withdraw money, sorting various important papers so that they are easily found and read.

But there are interruptions to his meticulous planning. Charley (Julianne Moore), a neighbor and fellow transplanted Brit, has been badgering George about dinner. Then there is Kenny (Nicholas Hoult), a student who has concern for George after seeing him packing up his office — and maybe stronger feelings.

That director Tom Ford would make a beautiful film is no surprise. But it's a rich, full beauty, every period detail attended to (Moore, very good in a small role, is a marvel of early '60s hair and eye shadow).

There's a richness to the emotion, as well. The look of the film establishes mood, and Firth enhances it greatly with his masterly portrayal of a man shattered by grief, which he masks through routine. As a gay man living in 1962, George is used to hiding his emotions, used to an interior life.

What makes Firth's performance so great is how he remains buttoned down, yet still lets us see his quiet desperation as powerfully as if he were shouting from the rooftops.

As beautiful as the film looks, Firth is the real reason that "A Single Man" is a fascinating film.