Constructed by Noah Buschel, this neo-noir stars Michael Shannon as a Chicago P.I. with — surprise, surprise — a don't-ask past that soon materializes before us. Indolent and soused, Shannon offers a brilliant performance, flashing a quirk for every occasion and moving like an ooze even after he takes on a high-pay, "hide and seek" case. Once he gets on the Los Angeles-bound Zephyr Express to follow his unnamed mark, we're on track for an unusual tale about loss and letting it be. Although it needs fine-tuning here and there, The Missing Person is a genre riff that entrances with its world-weary rhythms and its novel, hard-edged aesthetic.