David Wozniak is a jovial but irresponsible man who works as a delivery driver for his family's butcher shop in New York City. His life takes an unexpected turn when he learns that, due to a mix-up at a fertility clinic where he frequently donated sperm two decades ago, he is the biological father of 533 children. Not only does this revelation shock him, but it also comes with the news that 142 of these offspring have filed a class-action lawsuit to force the fertility clinic to disclose his identity. Overwhelmed by this startling information, David contemplates the implications of fatherhood on such an unprecedented scale.

As he wrestles with his newfound reality, David enlists the help of his friend and overworked lawyer Brett to counter the lawsuit and maintain his anonymity. Simultaneously, David decides to secretly get to know some of these children without revealing who he is. Through interactions with various individuals who unknowingly are his children—from a struggling artist to a talented basketball player—David begins to reflect on the meaning of family and responsibility. This journey of self-discovery leads him to make significant decisions that alter the trajectory of his life and relationships.