Overview: Whilst buying furniture from financially-stretched pensioners Anita and Brian Richardson, Archie discovers a piece of graffiti on the bedroom wall-paper which he has authenticated as being the work of Banksy, who was once the Richardsons' lodger. He displays it at a tatty art exhibition of his own where a glamorous gallery employee tells him it is worth a fortune and exhibits it for him. Unfortunately the Richardsons come clean to Archie, explaining that it is one of many forgeries perfected by Brian and given to a middle man whom they only know as 'Picasso' who sold them on for them. When things got uncomfortable, thanks to the earnest fraud officer Inspector Willoughby, Picasso disappeared. Willoughby now believes he knows the identity of 'Picasso' - Archie Daley. Jamie must retrieve the false Banksy from the gallery before the deception is discovered.