 After using considerable ingenuity to evade their pursuers, Rich Evans and his school chum Sean O Connor arrive at Boyne Castle. (See descriptions for parts 1 and 2). But the spies who have been chasing them across Ireland have gotten wise to their evasive tactics. What disguise will they use to entrap Evans and O Connor yet again? What is Tom Evans involvement in all this? And what is the "secret" of Boyne Castle? The Secret of Boyne Castle is a wild romp through 1960 s Ireland with the Irish countryside and highway system as a backdrop. It is an unusual thriller which will keep you on the edge of your seat as each episode unfolds right up to the final scene.