Wisdom's Way / The Fifth Man

A body is found buried in a shallow grave, in the grounds of a ruined monastery on a private island, just off the coast near Oakwood Sands. The body had not been there long. Who was he? How did he get there? Where and why was he killed? As the police investigations continue, a second body is found in another part of the island. Evidence is discovered there that could link this death to an armed robbery back in 2014. Why did Paul Gibbons act so strangely when he crashed his speedboat near the picturesque sandy bay? Why was he in so much of a hurry? Just who is 'The Fifth Man' and could a broach tell all?