Jonathan Creek: The Scented Room (1998)

A priceless painting disappears from a locked room and the owner, theatre critic Sylvester Le Fley, offers a large reward for its recovery, which tempts Maddy. Jonathan is quick to announce that he knows how the theft was done, but will not explain due to his dislike of Le Fley, who recently published a negative and disparaging review of Adam's show. Desperate measures are required to get him to co-operate, but the only clue he will reveal is that a spam sandwich is involved.