Summer isn't turning out quite as Frances planned. Her horse, Orlando, has colic, and then all her time is taken up with improving the riding of the vets' children.

'You can't refuse to pass on the information that other horsy people have handed down to you,' her mother says, and Frances reluctantly agrees.

Then Frances and her friends are persuaded to help out a family who are convinced there's treasure somewhere on the moor.

Perhaps there is. But it won't be where they expect.