Radiantly beatific, Angelina Jolie glows with mother love in bright red lipstick and a series of divine cloche hats as Christine Collins, a devoted single mother, in this fact-based drama directed by Clint Eastwood. In 1928 Los Angeles, while she was at work, her son Walter just disappeared. Months later, the police told her they had found him, but the boy they gave her was not her son. She was pressured by corrupt cops to accept the new boy as hers. When she persisted in pointing out that not only was this boy physically different from Walter but that his dentist and teacher were on her side, she was committed to a mental institution and told she could not leave until she dropped all efforts to prove that her son had not been returned.

Eastwood’s meticulous direction and the sheer outrageousness of the story make for absorbing drama, though the very strangeness of the underlying facts makes the material seem overpacked (the running time is almost two and a half hours) and its discursive unfolding diminishes the dramatic effect.

It is impossible not to bring Jolie’s public role as a devoted mother of six to her performance here. Once Hollywood’s most notorious wild child, Jolie has transformed her public persona into a sort of earth Mother Courage on behalf of her own multi-cultural brood and on behalf of all the world’s poor and neglected children with her work for the United Nations. All of that blends in to the ferocity she brings to this role, diminishing the power of the story. The stand-out performances here are Ryan as the indomitable inmate and Jason Butler Harner as the man who probably knows what happened to Walter.

An additional distraction is the effort to put three separate stories into one long drama. The first act is the boy’s disappearance and the horrifyingly absurd attempt to persuade Collins that another child is her son. The second is a “Snake Pit”/”One Flew Over the Cuckoo’s Nest” diversion after she is thrown into the state mental hospital, where she is subjected to abuse but meets another inmate (the always-outstanding Amy Ryan) whose honesty and courage helps sustain her hope. And then there is a third act, where Collins all but disappears as the crime drama plays out and we find out what happened to the boy and what happened to those responsible.