In a world where humans coexist with puppets—who are seen as lesser citizens—cast members of a beloved 1990s children's television series begin getting murdered one by one. Puppet Phil Philips, an ex-LAPD detective-turned-private eye, takes on the case at the request of his old boss in order to assist his former partner, Detective Connie Edwards.

Uptight and straight-laced, FBI Special Agent Sarah Ashburn is a methodical investigator with a reputation for excellence--and hyper-arrogance. Shannon Mullins, one of Boston P.D.'s "finest," is foul-mouthed and has a very short fuse, and uses her gut instinct and street smarts to catch the most elusive criminals. Neither has ever had a partner, or a friend for that matter. When these two wildly incompatible law officers join forces to bring down a ruthless drug lord, they become the last thing anyone expected: buddies.

Following a ghost invasion of Manhattan, paranormal enthusiasts Erin Gilbert and Abby Yates, nuclear engineer Jillian Holtzmann, and subway worker Patty Tolan band together to stop the otherworldly threat.