Especially in the second half, when Philippa the somewhat spoiled and beautiful opera singer goes on the trail of a murderer.
Her husband is on trial for killing a former girlfriend (the magnificent Rosalie Crutchley), and with Francis L Sullivan as the prosecutor, his chances look slim. He (Hugo Williams) tries to keep up his spirits, but underneath a light manner he is desperately worried.
So Philippa sets off to follow a musical clue, wearing the kind of hat the royal family are fond of (in her case, it protects her 40s pompadour hairstyle). It leads her to a sinister gothic school in the far north, where she is shown round by Marius Goring.
There are lots of good scenes in trains and railway stations, filmed on location. When they pull into York, we fleetingly see a traveller who looks uncannily like the murdered girl. But when we recognise one of the fellow-passengers as stalwart actor Ronald Adam, we are prepared for more drama...
I'd love to read the original book by Winston Graham. Writers of historical sagas (Poldark) often do their best work when young and writing about the contemporary scene.
It's a shame that Sullivan fades out of the story early, and Philippa's modern opera seems to consist of one scene. Obviously her singing voice is dubbed, but what about her speaking voice? It is very unlike the sarcastic, seductively nasal tones of her performance in Dear Murderer. Perhaps she just adopted a different voice for this character who, though flawed, is basically a good egg.