I'd seen one episode of "Colonel March of Scotland Yard" before and decided to start over at the beginning with this one. Almost no time is wasted in "The Sorceror" in introducing characters and situations at length, but this does not turn out to be necessarily a bad thing as the little exposition that is dropped in provides all we need to understand.
Boris Karloff really throws himself into the role of the eccentric and childlike but brilliant Inspector March -- he moved to London to film this series. He makes March's idiosyncrasies seem more reasonable than they ought to somehow, carries the plot along with dignity, and is believable when he must be passionate. Ewan Roberts as his "Watson" figure from the yard is aggressively normal to Karloff's iconoclasm, which makes for a good contrast.
The plot of this one is agreeable strange, avoiding dullness with a psychoanalyst who infuriates patients by hardly saying anything and his traumatized Holocaust-survivor wife. It's also an interesting look at the fifties' society's fascination with psychiatry just as the public was starting to become informed about it. Despite this series' focus on the occult the solution to the mystery is fair in its broad outline at least and doesn't rely on knowledge of the supernatural, which is a good thing.