When naval historian Dr Douglas Spalding is found dead in Portsmouth's Historic Dockyard, the Major Crime Team is adamant it is suicide. When another body is found in similar circumstances Horton is convinced they're looking at murder; but not so his bosses. The deaths have all the hallmarks of a cover-up at the highest level, but who is behind it and why? As Horton gets closer to the truth and uncovers a personal twist, someone is determined to stop him from finding the killer . . .