Kate DiCamillo’s 2003 children’s novel about a big-eared mouse with an inspiring case of shining-knight envy is one of the finest expositions for kids of loss, grief, reactive vengeance, and forgiveness. I was looking forward to seeing what Sylvain Chômet, who made the fabulously weird The Triplets of Belleville, would bring to this great yarn, which trusts small children enough to understand the concept of mixed motives and to empathize with hurt rats who hurt in return. Alas, for murky reasons, Chômet was bounced from the project. So Despereaux looks good, in a washed-out, Flemish-masters sort of way, but the delightful tale has been turned into an intermittently vicious CGI action movie in which the mouse (voiced by Matthew Broderick) who refuses to cower gets dumped down a well into a dungeon and shoved into a terrifying gladiatorial battle with a gruesomely drawn cat before he can even start saving the world from darkness and gloom. Clumsily wedged in like a TV commercial between deafening stunts, the emotional storytelling sinks without a trace, leaving you with only one flawed character to cling to—a morally challenged Cabbage Patch–like servant (wittily voiced by Tracey Ullman) who learns that every girl is somebody’s princess.