Hannah Bryson loves working with her brother, Connor, as marine architects. They complement one another perfectly, as Hannah is cool and analytical and Connor is idealistic with a passionate love of machines. Their job takes them all over the world, but their latest plum assignment is in their backyard in Maine. Hannah and Connor have the honor to prepare a Russian nuclear submarine, Silent Run, for a museum. On examination, they discover a weird hidden metal plate filled with scratches that resemble intricate symbols and geometric shapes. Before they can report it, Connor is murdered and an attempt is made on Hannah's life.

Devastated by her brother's death, Hannah seeks revenge. She doesn't trust the government agent who will not give her a straight answer. Instead, Hannah teams with Kirov, a secretive man with his own agenda. Both are driven by revenge. Hannah and Kirov search for the obsessed killer while attempting to solve the cryptic clues. The killer wants them eliminated from the hunt and will stop at nothing to have them out of his way.

Fans of Iris Johansen will be happy with this collaboration with her son, Roy. It reads like pure Johansen with added action, technical details and an international treasure hunt. The fast-moving plot never slows down. The authors have limited the romance and it's minimal within the storyline.