A cranky, retired author reluctantly embarks on a final book tour to help out a young publisher. Comedy,Drama n the surface, the storyline of "Best Sellers" seems simple enough. Young book editor Lucy Stanbridge (Aubrey Plaza), who recently inherited Stanbridge Publishing from her father, attracts famous but long-silent author Harris Shaw (Michael Caine) back into business after he unexpectedly has a new novel to offer. They set out on a publicity road tour in and around Boston and New York, and lots is learned about both of them, leading up to a revelatory finish. By turns it's poignant, wry, funny, or all three at once. It's a 'little' film, very human-centered, and really well done. Michael Caine is predictably excellent, so it turns out that the success of the film depends a lot on Aubrey Plaza's acting (is he going to steal every scene, or can she stand up to him?) since she's probably on screen the most of all. Turns out she does pretty well, and it's not just him that we end up interested in. The character-driven progress of the story is all about how Lucy tries to manage Harris through her publisher's agenda of getting the new book publicized versus his stubborn resistance ('crusty old codger' doesn't say the half of it). The script leaves a lot of questions hanging in the air. Why is Harris so cranky and at times downright mean to her, his own agent? Why is he an apparently self-loathing drunk and why hasn't he written anything in 40 years? What about her father, who was Harris's editor long ago? Is the new book going to take off, or her company going to go under? All these questions get clever and complete answers, and when they do, the story suddenly starts to cut a lot deeper and gain many new layers. I thought, though, a bit too much of the Reveal got packed into the last 20 minutes or so of Act 3. The long central Act 2 is all about the road trip, which is always teetering hilariously on the brink of collapse. Lucy is constantly driven to distraction, and Harris constantly looks so rumpled and dissolute that you wonder if Michael Caine himself is really that frail; is it all an act? There's a quietly brilliant set of scenes where Lucy gets fed up with Harris's recalcitrance and recruits fans to do readings from his new book instead, which then go viral on the Web. And another where devoted readers ceremonially burn the book after reading it (which makes pefect sense in context -- you have to see it). And the ending -- also very quietly done, but Wow. Everything is going to be all right. And it's satisfying, not just something that was pulled in out of left field. It makes perfect sense knowing what we know by then about Harris and his hidden history. What's an author going to do for 40 years except write?