Listen to the Moon by Michael Morpurgo 
 
The stunning novel set during World War One from Michael Morpurgo, the nation's favourite storyteller and multi-million copy bestseller.

May, 1915.

Alfie and his fisherman father find a girl on an uninhabited island in the Scillies - injured, thirsty, lost... and with absolutely no memory of who she is, or how she came to be there. She can say only one word: Lucy.

Where has she come from? Is she a mermaid, the victim of a German U-boat, or even - as some islanders suggest - a German spy...?

Only one thing is for sure: she loves music and moonlight, and it is when she listens to the gramophone that the glimmers of the girl she once was begin to appear.