22 is invited by a game company to playtest its unfinished virtual reality game, The Sea in a Box. Inside, a fishing village on the southern coast celebrates the Lantern Festival as villagers carry their household deities through the streets in a procession. There, 22 and three fellow testers find a female deity none of them has seen before, Cizhou Shenggu. The game relies on AI-simulated NPCs and system dynamics that produce features the developers never made. As the testers dig into the deity's origins, they find signs of interference from outside the game, with some hidden force quietly steering the NPCs. Meanwhile 22's sister, 33, notices company staff acting suspiciously in the real world. With a scheming company, NPC fishermen preparing a secret ritual and companions who may be hiding things, a wider conspiracy slowly comes to light. The single ONA episode blends fantasy, horror, mystery and sci-fi.