384 pages. A German secret naval weapon unleashed at the end of World War One.
This was one of Reeman's early books. I believe it was his sixth novel. As such, it has weaknesses not present in his later works. For example, he has a lady prisoner fall in love with the captain of the German raider on which she is held, despite not having a lot of interaction with him. Since I've read so many of his other novels, I was disappointed in this one.