Jessica Lidh's debut novel, The Number 7, is a ghost story that demonstrates how the dead can go on living through their actions.

Louisa, 16, goes with her father to clean out his childhood home in Pennsylvania after his mother dies, and it is his first visit home since he left years before. While exploring the attic, Louisa finds an antique phone, and when she picks up the receiver, she can hear someone breathing on the other end. The problem is that the phone is not connected. Later, the phone starts to ring, and when Louisa answers it, a woman begins telling her a story about Louisa's grandfather, saying that he was a murderer. Louisa wants to ask her father about this, but he does not like to talk about his parents or his childhood.

Her father makes the decision to move the family from North Carolina to Pennsylvania, a unilateral decision about which Louisa seems neutral and her older sister Greta is not happy. Their mother died five years previously from breast cancer, and that is another thing the family does not discuss.

Louisa starts school and finds herself the focus of attention of two boys: cheerful Gabe, son of the local grocery store owners, and moody mysterious Chris. Her father takes an interest in a neighbor, Rosemary, who turns into a good friend, and Greta slowly adapts. In between school and homework, Louisa listens to the story about her grandfather, Gerhard, a man she never met, while she struggles with her own issues, family and memories.

The novel is engaging, and Louisa's pragmatic approach to the mysterious calls from beyond is refreshing; she is unnerved but nevertheless pays attention and wants to hear about her grandfather and the actions he took while living in Sweden. It was a neutral country during World War II but nonetheless sold iron ore to Nazi Germany and allowed the Nazis to transport soldiers and materials to Norway. Louisa's grandfather was the conductor of one such train -- the eponymous Number 7 -- and while he was cooperative at first, he decides to work with his twin brother Lasse to defy the Nazis.

Lidh tells a good story, and she has a remarkable grip on how teens think and act. Louisa is level-headed and becomes confident, exhibiting growth in all her relationships, including her family. Some of the side stories, such as the girl upset at Louisa's involvement with Gabe or Greta's bout of cutting, seemed superfluous, and it would have added to the book to have a note about activities in Sweden during World War II. Still, minor flaws can only lead to improvement, and readers will look forward to seeing more from this talented author.