I agree with everything you say about Trish van der
Veer, but I think actually Peter Falk put in a poor performance in this one. He takes on the "arrogant
and goofy" persona that became his trademark in the later episodes of the original series and all the episodes of the 1980's revival. I liked him a lot better as the "humble and mildly eccentric" personality that he started out with.
Still, this is an outstanding episode. Kay Freestone
is a very complex character, unlike most of the murderers. To Mark McAndrews she is a scheming, cold
person, but she also has a tender, caring side for Valerie Kirk.