I am not really giving anything away when I say that before I even watched it I knew that there was going to be no sensational revealing of what happened to Lord Lucan.
It would have been a big news story some time previously if there were.
It is interesting, although three episodes is a bit too long.
This is about the son (Neil Berriman) of the murdered Nanny and his quest to find the man responsible for killing the mother he never knew, he being given up for adoption by her. He did not find out who his really mother was until after his adoptive mother had passed away.
It is fair to say that Berriman has/had become completely obsessed with his quest. At first it seemed reasonable, but after seeing, briefly, what his wife thought of it all, it became clear that his whole life became revolved around the search for Lucan.
Fortunately his cohort, the investigative journalist Glen Campbell, was with him and kept a sober view on everything.
Even when Berriman was convinced he had found Lucan, Campbell was not.