This is a terribleTerribleTERRIBLE episode. It wasn't the slightest bit frightening as some reviewers have said. It was just stupid, made no sense. The acting was below the usual level, the motivations, unconvincing, the resolution, unbelievable.
But there is a larger problem with Morse for modern-day viewers. That is that they are tooTooTOO long, too slowly paced. It isn't really the fault of the show but the familiarity with present-day story-telling. When Morse was made, producers didn't believe that audiences could follow more than one story line at a time, hence that linear, unexciting unfolding of the story. The Inspector Lewis shows were able to go a short way into multiple threads, but were burdened by the fact that most of the murderers were played by terribly overacting middle-aged women who inevitable were screaming at he end of the episodes. The Endeavors, however, are brilliant, respect the audience's ability to be able to keep track of more than one storyline at a time.
I watch Morse, more as a duty to the three series' reputations but don't enjoy them, and anxiously check the time elapsed to see how long I have to endure these endlessly dull shows. Sorry Morse lovers, but these are too dated to be anything but yawn-producers.