Living in Edinburgh, Philippa Langley loses a work promotion to a less experienced better-looking woman. She unsuccessfully confronts her male boss that her ME has never affected her work. Distraught, her ex-husband John, who helps with their two teenage boys, tells her to keep her job as they need the money.

Philippa attends the play Richard III, and identifies with Richard whom she feels was unfairly maligned as a hunchback, child killer, and usurper. She begins to have visions of Richard who appears to her. She joins the local Richard III Society who believe he was unfairly vilified by Tudor propagandists.

Philippa stops going to work, manages her ME with medication, and begins talking to her Richard III apparition. Her research shows some sources say he was buried in 1485 in the Leicester Greyfriars priory choir area, while others say his body was thrown into the River Soar. After Greyfriars was demolished in the 1530s Reformation, Leicester mayor Robert Herrick around 1600 had a shrine built in his garden saying “Here lies the body of Richard III, sometime king of England.”

Philippa attends a lecture in Leicester on Richard, lying to her ex-husband about it being a work trip. She meets Dr Ashdown-Hill, who is publishing a genetic genealogy study on a Canadian direct descendant of Richard III's sister. He tells her to look for Richard in open spaces in Leicester because people for centuries have avoided building over old abbeys. While walking around Leicester looking for the ancient site of Greyfriars, and seeing apparitions of Richard, she gets a strong feeling that an “R” painted on a car park is the site of Richard's grave. Returning home, she confesses her activities to John.

Philippa contacts University of Leicester archaeologist Richard Buckley, who dismisses her ideas, but when the university cuts his funding, he gets back to her. Buckley finds an old map of Leicester marking Robert Herrick's property, showing a possible public shrine in his garden. They overlay a modern map of Leicester and find that the shrine may be in the middle of the car park that Philippa had felt strongly about.

Philippa and Buckley team up. She pitches it to Leicester City Council. Richard Taylor of the University of Leicester advises that her amateur “feeling” is too risky. The Council still approves her plan for the publicity, but when ground-radar finds nothing, funding drops out. She turns to the Richard III Society to crowd-fund her “Looking For Richard,” and the money comes in from around the world to fund three trenches.

On day one of the dig, Buckley tells Langley that the dig certificate has been signed, but does not tell her that her name has been omitted. Philippa gets Buckley to start trench one at the painted “R” spot, and they immediately find the legs of a skeleton. Buckley thinks it is an extramural graveyard for monks. Philippa also confronts Taylor onsite for now falsely claiming credit for leading the project. She then insists on stopping all work to focus on exposing the complete skeleton in trench one. Buckley angrily relents and goes home while the crew digs the skeleton. The osteologist soon realises that it is indeed Richard III, with the correct kind of death-blow to the skull, a 30-year-old male, and a badly-curved spine. All found on day one.

University of Leicester leaders rush in to takeover the project. They re-hire Buckley. In February 2013, Taylor announces their findings to the world at a University of Leicester press conference, at which Phillippa is largely sidelined, even by Buckley. Buckley is later given an honorary doctorate by the university.

Richard appears to Philippa a final time at Bosworth Field; he thanks her, and rides off. Richard is shown getting a funeral fit for a king in Leicester Cathedral. The closing credits say the royal family's website has reinstated Richard as the rightful King of England 1483–1485, so that he is no longer regarded as a usurper. Langley was awarded an MBE for her work.