Rating:

Poignant as it is funny and entertaining as it is heartbreaking, “Up in the Air” is a story that’s as much of its time as any in recent memory. It’s an instant classic, and the best film of 2009.

Director Jason Reitman is now 3-for-3: every one of his films — 2006’s “Thank You For Smoking,” the following year’s “Juno” and now “Up in the Air” — has been one of the best movies of its respective year. Reitman also co-wrote, adapting the script from the novel by Walter Kirn.

“Up in the Air,” plot-wise, has more in common with “Smoking,” as it follows a male protagonist in an outrageously loathsome profession who is nevertheless somewhat likable. But while there are some laughs, the tone is all different in “Up in the Air” — and the script goes to some very surprising places.

George Clooney stars as Ryan Bingham, a consultant with a firm hired by companies to fire their employees. He travels around the country, for about 300 days a year, living in hotel rooms and airport lounges and collecting a superhuman amount of frequent-flyer miles.

Ryan may lack any human connection whatsoever — but not only does he enjoy this lifestyle immensely, he even gives motivational lectures to others on how they can become just as detached as he is.

Along the way, Clooney meets Alex (Vera Farmiga), a frequent-flying version of himself with whom he has an affair, as well as Natalie (Anna Kendrick), a colleague in her early 20s with a plan to cut down on expenses by firing people by teleconference instead.

The relationship between Clooney and Farmiga here, from beginning to end, is one of the best-handled in any recent film. And watch the especially heartbreakig sequence when they attend the wedding of the sister (Melanie Lynskey) with whom Clooney’s never been especially close.

What could be more perfectly in tune with the zeitgeist at the end of the ’00s as a movie about a guy who’s job it is to fire people? I suspect many viewers of the film will relate to it in a big way for that reason. But the topicality also never gets too obvious or heavy-handed.

But that’s not all that’s great about this film. The acting, starting with a never-better Clooney, is strong across the board, and Reitman gives the film a look that’s just right. And perhaps best of all, the ending is legitimately surprising.

The story could very easily have gone in one direction, but instead ends in a much more believable and satisfying way. It doesn’t sell out, or reach a conclusion that doesn’t feel right.

Even though it’s based on a novel from 2001, “Up in the Air” is as 2009 as a movie can possibly be. No movie that doubles as the quintessential film of the Great Recession has any business being this entertaining.