The Dark Island is a six-part British television miniseries, produced by Gerard Glaister for the BBC.
A naval team descends on the area to deal with the torpedo accompanied by Nicolson, an intrigued security officer.
Further investigation of the torpedo reveals an international spy kit, the contents of which include a Finnish passport, British and Swedish currency, and most intriguing of all, a fragment of sheet music.
David Silver of Glasgow wrote the most common and famous words to the theme after the TV series appeared.
Another set of lyrics was written by Stewart Ross of Inverness and is also quite well known, having been recorded by Calum and Fiona Kennedy as well as Daniel O' Donnell.