"The Lights Go On Again" is a satisfying ending to the Guests of War Trilogy. The 3rd installment switches things up by focusing on Gavin rather than Norah, and finds the Stoakes children getting ready to welcome the year 1945. Norah and Gavin are still living with their Canadian family, the Ogilvies, but all around there is talk of the long war finally coming to an end. Norah is ecstatic: they'll soon be going home to be with their parents, and while she'll miss the Ogilvies and her best friend Paige, she is English and England is where she belongs. Gavin, on the other hand, secretly feels differently. Gavin was very young when he left England, and no longer remembers his parents or their former home. Gavin feels Canadian, and is frightened of what the end of the war means for his way of life. He is terrified at the thought of leaving safe Toronto and Aunt Florence for the unknown, war torn England he doesn't remember.
Then, tragedy strikes and Gavin has to make the most difficult decision of his young life. While the world starts to relight the lamps extinguished by war, Gavin must decide what it means to be brave, and how to live life in spite of your fear.