The Secret of Boyne Castle (television title) or Guns in the Heather (theatrical title) is a wild romp through late 1960's Ireland with two school chums being pursued by spies from an unknown state. After having escaped from the "bad guys," (see description in episode #1) Rich Evans and his friend Sean O'Connor are pursued cross-country by the spies who captured them, with the Irish countryside and highway system as a backdrop. While in captivity the two school chums noticed that one of their captors wore a peculiar looking ring. This ring more than once gives away the head spy while Evans and O'Connor continue on their journey to Boyne Castle. All the while Rich is wondering what his brother Tom's involvement in all this is. The "secret" of course lies at Boyne Castle.