The TV series theme tune "reached the top five in the UK singles charts" according to the DVD sleeve notes. The music score by Irish group Clannad was also nominated for a BAFTA Award. It was later famously used in the movie Patriot Games (1992), which also deals with the hunt for IRA terrorists.
Only about ten to fourteen days filming took place in Belfast in Northern Ireland. Most of the production was shot in the city of Leeds, in West Yorkshire, England.
The television mini-series was made and first broadcast about seven years after its source novel of the same name by former-ITN correspondent Gerald Seymour had been first published in 1975.
The series received an cut-down release on VHS before being distributed in full in 2007 on Region 2 by Network DVD.
Lead actor Ray Lonnen benefited playing an Irish character from having participated in a Belfast Arts Group as a youth.