The Under Groove follows a seasoned grifter as he becomes entangled in a psychological mystery far stranger than any con. After being robbed by a woman on the subway-who appears to possess a third hand-he tracks her to a quiet Manhattan home. But nothing is as it seems. The woman, apparently innocent and childlike, is under the care of a nurse who reveals her to be suffering from a dissociative disorder. As the con man tries to retrieve what was stolen, he's drawn into a deeper web of mental fragmentation, deception, and criminal psychosis, questioning his own past as he unravels hers.