Tom's summer holidays start disastrously when his brother catches measles. Their plan to build a tree house has to be postponed and, worst of all, Tom has to spend his quarantine with his uncle and aunt in their small flat. He cannot imagine what he will find to do.... and what he does find is indeed beyond imagining.

Tom has discovered the sort of garden he's always dreamed of. But why does no one else mention it - and what does it have to do with the grandfather clock?

Tom has always visited the garden in daytime. One night, he finds the garden dark and threatened by a storm.

It has been a magical time for Tom, exploring with Hatty all the secret places of the garden. But it still has many surprises in store....

Hatty's accident seems to have brought about a change in her. And time in the garden seems to be changing its pattern, too....

Hatty and Tom have started on their greatest adventure - skating all the way to Ely.