It is the 1980s. Henry Oxshott is a cat of medium intelligence, lazy but well bred. He lives in a flat which was left to him by one of his relatives who spent most of her time buying antiques and paintings which now fill the flat. He has no job, no income and is down to his last few pounds. His flat is dirty and needs to be cleaned, so when the local cleaning company offer the services of a cleaner for free he jumps at the chance.

The cleaner turns out to be Finch a bulldog, ex-Army, honest, older and wiser than Henry. Finch's arrival coincides with a letter from solicitors acting on the estate of Henry's deceased Uncle Bartholomew (a famous explorer). At the reading of the will a mysterious and beautiful cat called Daphne appears, as well as Henry's other Uncle, the nasty and greedy Uncle Crispin. To everyone's surprise Daphne inherits Yews Hall, the family ancestral home in Sussex. Uncle Crispin makes a mysterious reference to a painting but all he inherits is a walking stick. Henry gets given a Bible.

With Finch's help, Henry decodes a message in the Bible suggesting that his real bequest is at Yews Hall. With great excitement, they embark on a treasure hunt like no other and do battle with dark forces to find the real prize, which all along is hidden in plain sight.