This is the third book in Jemma Spark's Jill series which is a follow-on from the original Jill books by Ruby Ferguson. Jill Crewe is going pony trekking, just as she had done some years previously. She had met a marvellous family called the Merrivales when she stayed at their farm in Dartmoor. Now, she is returning to trek around the moor with them.

Before she leaves on this innocent adventure, she becomes entangled with a mysterious young man called Mungo. He insinuates himself into her life and somewhat reluctantly she agrees that he tag along on the trip to Dartmoor.