Going on holiday to France just before the German invasion in 1940? A recipe for disaster. That's exactly what Alice and Tom Froston do – and soon find themselves in more danger than they could ever have imagined.

Sent back to Paris by their parents, the train they are travelling in is bombed – but that is only the start of their desperate attempts to get home.

Along the way they face capture by the advancing enemy and encounter a cast of unexpected allies: a downed RAF pilot, a nun with unexpected talents and even a French noble, amongst many others.

With German forces closing in on the British at Dunkirk and France on the brink of surrender, will Alice and Tom find a way back to safety?