Circulation investigates a purgatory where the dead still have human form and the world around them looks the same as the living world. The people trapped in this purgatory start to develop the instincts that animals are naturally born with. Gene, a retiree vacationing in Baja, is learning the instincts of a spider and stumbles upon a woman who is destined to be reborn as a caterpillar/moth. The film explores a world where human and animal intertwine as one.