Sophie, Marina, Quigs, and their teacher decide to excavate an air raid shelter from World War II located in their London schoolyard. When they exit the shelter, they find that they are in the same location, but they have been transported back to September 1940. They make their way to Quigs' ancestor's house, Esther, who kindly takes them in. The children and their teacher must then blend in with society, while they desperately try to find a way to get them home again.
The Secret Shelter recreates what life was like in London during World War II, but I found the story to be too predictable. One event seemed to end conveniently; so another one could start right after it. For instance, the air raid would start just after dinner had ended. Otherwise, the book gives good detail about the London air raids and how the morale of many Londoners was tested to their limits during the times. This is an easy read, ideal for readers who like short books.