Mrs. Morris is a mother living in a peaceful suburban neighborhood in an undefined near-future. She spends her afternoon doing household chores, catching up with her friend Helen over an audio-visor, and intermittently checking on her daughter's unusual playtime activities. Her attitude toward children shifts continually between tolerant amusement and dismissive frustration.

Mink is the seven-year-old daughter of Mr. and Mrs. Morris. Energetic and decisive, she acts as the leader of the neighborhood children who are under the age of ten. She spends her afternoon rushing around gathering household items and communicating with her new friend, firmly believing she is helping orchestrate a worldwide event.

Drill is a mysterious, unseen figure who befriends the neighborhood children. He directs the kids in their game of "Invasion," promising them a world where they rule over the adults. He remains invisible to the older characters, communicating his observations about the adult-child divide exclusively through Mink.

Joseph is a twelve-year-old boy in the neighborhood. Because of his age, the younger children exclude him from their activities. He represents the older children who no longer possess the specific imagination required to participate in the new neighborhood obsession.

Peggy Ann is a neighborhood child who initially participates in the games. She eventually becomes frightened of the "Invasion" activities, leading Mink to declare that she has grown up too suddenly to play anymore.

Mr. Morris is Mink's father and Mrs. Morris's husband. He spends the afternoon away at his job, completely removed from the peculiar activities happening in his suburban neighborhood.

Helen is Mrs. Morris's friend who lives in Scranton. She converses casually over the audio-visor, sharing cake recipes and chatting about the strange games their children are playing.

Tim is Helen's son, living in Scranton. Much like the children in the Morris neighborhood, he spends his afternoon playing the "Invasion" game with an invisible yo-yo.

Anna is a young neighborhood child who plays with Mink. She acts as a secretary during the game, struggling to transcribe the complex instructions that Mink dictates to her.