Keith Reynolds impulsively buys a secondhand metal detector and uses it during a camping weekend with his wife, sister-in-law and her husband. The discovery by the metal detector and subsequent illicit removal of a handgun from a disused Ministry of Defence (MOD) site, leads to Keith being implicated in the unsolved murder of a senior policeman's brother. The policeman is due for retirement, but has vowed to catch his brother's killer. With only Keith's fingerprints on the gun and the illicit way he smuggled it out of the MOD grounds, Keith has difficulty proving to the police how it came to...