UCOS is called to Buckingham Palace after a painting from the Queen's private collection is discovered to be a fake. The handsome Sir Tim, who oversees the collection, explains the investigation is top secret because his predecessor was found to have 'borrowed' paintings. Sandra doesn't want the case, but expert help is soon at hand when the aptly named Totty Vogel-Downing is seconded from art fraud to UCOS.
While Sir Tim tries - and succeeds - in charming Sandra, Totty discovers thumbprints on the canvases. Tests prove both fakes were painted in 1978 by an artist and political activist who committed suicide after a fire destroyed his studio. Old files suggest the fire could have been arson, aimed at a Kurdish sweatshop next door. Sandra and Jack visit a Bengali family who were injured in the blaze, while Gerry and Brian learn that remains of a white rat were found at the studio. The animal was too exotic to live in a warehouse naturally.
Jailed arsonist Pat the Rat says the rat must have been covered in petroleum jelly and used as a firebomb. Lists of clients from top London galleries link Pat to George Wilson, a notorious career criminal. Wilson escaped arrest 10 years earlier during Gerry's watch. When Deputy Assistant Commander Bevan blamed Gerry, the detective punched his superior - an offence that led to his early retirement from the force.
With Gerry ordered off the case and everyone apparently involved in the fraud operation dead, there seems little left to go on. Then Gerry breaks the rules to visit the dead artist's mother and discovers a link to someone close to the investigation.Source: