Director-writer Martin Hynes shapes his first movie into something emotionally truthful, painfully funny and vibrantly alive. It’s a near-perfect road movie, since you don’t want the ride to end. Oregon teenager Mercer White, played by a subtly sensational Lou Taylor Pucci, hits the highway in a stolen car to track down his half-brother, Arlen (Jsu Garcia), who doesn’t know their mother has died. In concise episodes that rim over with the pleasures of the unexpected, Hynes deepens Mercer’s encounters with characters played by the superb likes of Jena Malone, Nick Offerman, Judy Greer, Maura Tierney and a knockout Bill Duke. Hynes’ chief inspiration was a cellphone left in the car by the owner, who keeps nagging and nurturing Mercer throughout the trip. The throaty voice, which sounds like a sexy angel with a yen for wicked hell, belongs to Zooey Deschanel, whose larynx steals the show before the rest of her even shows up. Deschanel is the total package: talent, looks, smarts and a gift for putting magic into whatever she touches. Check out her CD, She & Him: Volume One, with M. Ward, whose beguiling songs dot the Go-Getter soundtrack. Together Deschanel and Pucci discover the essence of Hynes’ movie: its grieving heart. This one’s a keeper.