When an old Israeli Defense Forces friend recounts a nightmare in which he’s pursued by a pack of ravenous wild dogs, filmmaker Ari Folman decides it must be related to an incident in September 1982, when Lebanese Christian militias massacred thousands of Palestinians as the IDF stood by, doing nothing. Realizing that his memories of that grim occasion have been erased, he travels around Israel, interviewing old acquaintances and former soldiers about what, exactly, happened.

Folman’s expertly hand-animated, Oscar-nominated documentary is a memoir of sorts, mixing evocative personal reverie and candid recorded interviews to revisit an infamous event known as the Sabra/Shatila massacre. But it is more than a former soldier’s inner war diary: it’s a meditation on the curious operation of memory by a man attempting to excavate his own repressed psychological distress. Vital, vivid, and sobering, you’ve never seen another film quite like “Waltz.”