The fox called again. Its eerie cry echoed into the night. The sound wove in and out of the night garden, and into Tilly's dreams.' One night, awoken by a strange noise, Tilly looks out of her bedroom window and sees a wild fox watching her from the lawn.

Tilly follows it through a hidden gate and is amazed to discover a secret, moonlit garden.

She returns the following night but this time a young girl called Helen is already there waiting for her.

Tilly is delighted to have found a new friend, but is Helen real or is she a ghost?