The Mystery of the Disappearing Cat

The Mystery of the Disappearing Cat (1944) is the second in the Five Find-Outers series of children's mystery novels by Enid Blyton. It was published by Methuen and Co Ltd and follows the first book in the series, "The Mystery of the Burnt Cottage". It tells of a stolen cat the group of children work to uncover.
Plot.
Luke, a friend of the Five Find-Outers, is working in Lady Candling's garden when her valuable Siamese cat is stolen. The Five Find-Outers and Dog work to solve the case.
Characters.
The Main Characters
Suspects
Summary.
It all takes place next door to Pip and Bets Hilton, when Lady Candling's prize cat, Dark Queen (a valuable siamese), disappears right under the nose of Luke, the gardener's help. Mr Tupping, the gardener, is a nasty piece of work and the children immediately decide it would be great if he were the thief! But how could he be, if he wasn't even there when Dark Queen was stolen? All the evidence points to poor young Luke, Mr Tupping's helper, but the Find-Outers simply can't believe Luke is the thief.
There are a couple of other possible suspects in Lady Candling's staff, such as Miss Harmer the cat handler, and Miss Trimble, who takes care of the roses. They're all pretty sure it was Mr Tupping...but how on earth did he do it? The answer to the mystery is very simple and pretty clever. Mr Tupping stole Dark Queen in the morning, then painted a small patch of cream-colored paint to another cat's tail to disguise it as Dark Queen, whose tail was bitten by another cat, resulting the creamy patch on its tail. Then he made Luke work beside the cage all day, so that he could be the top suspect of the case. In the afternoon, Mr Tupping hopped into the cage, rubbed the paint off the cat's tail with a rag soaked in turps, and then announced Dark Queen was gone! At last, Mr Tupping was caught and shown that he had been mixed up with dog thieving cases before.