A Patch of Fog is a 2015 British thriller film directed by Michael Lennox starring Stephen Graham and Conleth Hill, set in Belfast.

A famous author, Sandy Duffy (Conleth Hill), wrote his well-known and only novel, "A Patch of Fog" nearly 25 years ago.

Still riding the success of his only publication, Sandy has developed a shoplifting addiction and gets caught by a security guard, Robert Green (Stephen Graham).

They agree to meet that weekend for another drink, at which point Robert will turn over the disk containing the video.

Robert leads Sandy to some railway tracks and gives him a coin flattened by a passing train and keeps the other for himself as a symbol of their new friendship.

During the tour, Sandy explains that he doesn't have a copy of his famous novel, but has the original manuscript around the house somewhere.

Feeling relieved, Sandy resumes his life teaching and hosting the talk show.

Phoebe drops something and Robert picks it up; he is enraged to discover that it is the deformed coin he gave to Sandy.

Sandy explains that he had the delivery men remove all of Robert's furniture and that he ordered an entirely new living room set.

Eventually, he finds Sandy's original handwritten manuscript of "A Patch of Fog," which is shown to be written by his father.