In Seattle, Washington, a crew of Reapers, who live and work among the living and whose job is to gather souls of people who are about to die, find themselves confronted by change, as their habitual meeting place, the Der Waffle Haus restaurant, burns down on the same day that their boss and head reaper, Rube, disappears (having "gotten his lights").
The team soon meets their new boss, Cameron Kane (Henry Ian Cusick), a slick businessman who died falling from the World Trade Center on September 11, 2001. He outfits them with color-coordinated smartphones and treats them to luxurious accommodations, teaching them all that, as Roxy (Jasmine Guy), a local police officer, puts it later, "nothing we do here matters." This tutelage leads the Reapers to perform such misdeeds as Roxy saving those they were to Reap, or Mason (Callum Blue) abusing immortality for financial gain, or Daisy (Sarah Wyler) letting a soul wander, instead of showing him "his lights", and otherwise selfishly focusing on their wants.
Georgia "George" Lass (Ellen Muth), the cynical and humble narrator, is fired from her office job at Happy Time Temp Agency when, after she loudly chews out an incompetent employee named Amy for delivering a report late, the employee quits and sues the company for harassment.
Meanwhile, George's bitter and highly neurotic divorced mother, Joy (Cynthia Stevenson), who never got over George's accident five years earlier when she was "killed" by a flying toilet seat, struggles to make it in the world as a writer and grievance counselor to parents who lost their children in violent deaths. George's younger sister Reggie (Britt McKillip) is a rather socially awkward and insecure 16-year-old attending high school but secretly is dating a popular school athlete named Hudson (Jordan Hudyma), who appears to be even more in love with Reggie than his "real" girlfriend--but, due to boundaries in high school social cliques, they only see each other in secret. After Hudson ends up hospitalized following a severe car accident, Reggie runs into George (appearing as her alter-life Millie Hagan) multiple times.
George ends up admitting her identity to her sister Reggie. Despite Reggie casually believing herself mad and refusing to believe what's going on, George finds herself reminiscing with Reggie, helping her prepare for the death of her boyfriend Hudson. During this time, George and Reggie begin to bond and be the sisters they weren't when George was alive. Later, Reggie asks to move in with George, even though she's dead. This appears to cause friction between Reggie and Joy, as the latter believes George is dead and gone (which is only half right). After George reaps Hudson, who passes on, Reggie attempts to kill herself by getting behind the wheel of George's red 1967 Mustang car (which she had acquired from a dead person in the series years earlier) and driving at a reckless speed. After George stops her, she realizes she can no longer see her sister anymore. Accepting that, Reggie visits George's grave one more time, before urging Joy to move on. Joy suggests that they go on a vacation.
Meanwhile, George's fellow Reapers confront Kane and, learning he withheld 'reaps' and deliberately tempted them to let the "pebbles" of their misdeeds cause "waves" of evil elsewhere, find themselves trying to figure out how exactly a fellow Reaper can be killed as they shoot, drown, and finally dismember and cremate Kane, whose ashes are then shot into orbit along with those of Murray, the cat belonging to George's highly crazy boss Delores. At the launch, Delores arrives and tells George that the employee who had sued her for harassment had done so at several of her previous jobs, and George is reinstated, now with a promotion to a corner office.
As Mason, Roxy, and Daisy walk away from the launch, wondering who their new boss is, the movie closes with George outside her former mother and sister's row house, watching from a safe distance as they pack up their car and drive off. After they have gone, George finds herself suddenly showered with Post-Its magically falling from the sky, like the Post-Its their former leader Rube used to deliver their Reaps. Realizing she's been selected by the powers-that-be as the group's new leader, she says "I am so fucked!"