Boston Police Department detectives Nick Walker and Bobby Hayes stumble upon a fortune in gold while executing a drug bust. Driven by the desire to provide a better future for his wife, Julia, Nick buries his share in the backyard, only to feel instant remorse and decide to return it. However, fate takes a cruel turn when a violent confrontation with criminals during a warehouse raid leads to Nick's tragic demise at the hands of Hayes, who wants to prevent him from returning the stolen gold.
After his death, Nick finds himself in limbo, navigating a surreal whirlpool that transports him to the office of Mildred Proctor, the director of the Boston branch of the Rest In Peace Department (R.I.P.D.). She explains that this unique organization recruits deceased law enforcement officers to patrol the afterlife and capture "Deados"—spirits unable to transition to the other side, instead manifesting as monsters on Earth. To avoid a dismal final judgment, Nick agrees to join R.I.P.D. for a hundred years and is paired with a weathered ex-U.S. Marshal, Roy Pulsipher, who has roots dating back to the 1800s.
As they return to Earth for Nick's funeral, he discovers that R.I.P.D. agents take on avatars that humans perceive. His avatar appears as an elderly Chinese man named Jerry Chen, whereas Roy's form is an alluring Russian woman named Opal Pavlenko. Nick’s attempts to communicate with Julia go awry, leading him and Roy to investigate a suspect, Stanley Nawlicki, who bizarrely shifts from his avatar to his monstrous appearance under the influence of cumin powder. The chase escalates, culminating in Roy pushing Nick off a 20-story building, but it’s Roy who ultimately puts an end to Nawlicki with a soul-killer bullet, erasing him from existence.
Amidst the investigation, Nick harbors suspicions that Nawlicki was safeguarding the stolen gold, which motivates him to persuade Roy to dig deeper. Their inquiries lead them to Elliot, Roy's informant, whom Nick tricks into revealing Hayes' location. Their pursuit takes them to Nick's former residence, where Hayes retrieves the buried gold, casting doubt on Nick's integrity in Julia's eyes. A tense altercation between Roy and Nick ensues over the gold, which leads them to follow Hayes to a bus depot. There, they confront a formidable "Deado" named Pulaski, but their attempt at intimidation backfires, leading to a sensational escape and chaos that makes headlines.
Furious, Proctor suspends Nick and Roy from the case, warning them of impending erasure. Undeterred, they continue their investigation, discovering that the gold is a crucial part of the Staff of Jericho—an ancient artifact capable of reversing the passage between life and the afterlife. A confrontation with Hayes reveals him to be a Deado himself, having brokered a deal to linger on Earth after his death. He removes his charm, revealing his true monstrous form, and is subsequently captured by R.I.P.D. agents.
However, Hayes, with other Deados, manages a daring escape thanks to a time-slowing device. In a bid to assemble the Staff of Jericho, he kidnaps Julia, intending to use her as a human sacrifice. The dire situation escalates, leading to a climactic battle where Nick and Roy strive to thwart Hayes' malicious plans. In the midst of the chaos, Nick fights valiantly to save Julia, but tragedy strikes as she succumbs to her injuries. Their emotional farewell is heart-wrenching, filled with both love and sorrow.
In a surprising twist, Julia is revived in the hospital, granted a second chance at life through Proctor's intervention, who acts out of regard for Nick. Proctor reinstates Nick with a warning, while Roy is given an additional 53 years at R.I.P.D. Knowing Nick's discontent with his avatar, Roy goes the extra mile to arrange a new one for him—much to Nick’s chagrin, it turns out to be that of a ten-year-old girl scout, leaving room for more unexpected adventures ahead.
