Jack is a software programmer who specializes in algorithms that model the behavior of swarming animals like ants and bees. When the novel begins, he is an effective stay-at-home dad who is exasperated with, and concerned by, his wife’s increasingly-odd behavior. Jack values integrity, which is ironically what leads to the loss of his job. Though he is fired when he threatens to expose damaging information about the CEO, he does not regret his decision; whenever Jack makes the right decision, he is at peace with himself.

Jack’s main characteristic is his meticulous, resourceful nature. He reflects: “I’m not passive, I’m thoughtful” (74). It is this thoughtfulness that allows him to solve the novel’s many problems on the fly. Jack is not merely an intellectual, however. He is brave, loyal, and capable of righteous fury. He is the first to enter the swarm’s hunting grounds to find the rabbit that holds the key to the nanobots’ behavior. Then, after almost dying, he goes outside again to save the life of an injured colleague.

Jack also acts out of foresight. When he risks his life to kill the swarms, it is not simply because he wants to live. Jack understands the implication of the