Case of the Missing Marine

Zack, Jillian, and their dogs are invited to Buckingham Palace, where they are thanked for recovering priceless artifacts, only to learn that Jillian's brother, a US Marine working on a top-secret project with MI6, has gone missing. As Zack investigates, he uncovers that many foreign governments are eager to obtain the confidential work her brother was involved in. The story follows their mystery-solving adventure filled with humor and intrigue, set against the backdrop of international espionage and personal stakes.