The finale is a definite improvement over the previous episode, but still a little less enjoyable then the usual Durbridge penned series finales. If I'm honest my suspicions as to the killer's identity were proven right, it's all the result of the story of the pen.
It's still an enjoyable episode with lots to enjoy, plenty of twists, one event I truly didn't see coming, so I applaud them for that at least. The action scenes are a little far fetched, and perhaps hard to believe, maybe slightly different casting would have been better. A quite grown up episode, with bad language and drug addiction references.
Gerald Harper was excellent throughout, no wonder he'd return in another Durbridge Mystery, A Game of Murder, a much better overall series in my opinion.
A complex story, some facts are held from the viewer early on, which throws you off track, but all in all it's a decent serial. 8/10