In some ways, this is the last great film of the original Universal Studios based horror cycle of the 1930's. It was certainly the last horror film with a lavish A-level budget and it shows in the lighting, decor, SPFX and vast sets.
The story is a familiar one, Victor Frankenstein's son returns and revives his father's dormant monster in a bid to prove his father's genius.
In fact young Wolf Frankenstein (Basil Rathbone) seems locked in a sort of Freudian death spiral with the unquiet shade of his father, a matter symbolized by the monster and all his lumbering symbolism.
This is a great looking film, Castle Frankenstein is a sumptuous German expressionist feast to the eye including a sulphur pit and what appears to be a walk in fireplace!
Alas the story is all but undone by an over-ripe hammy performance from Rathbone ably assisted by Donnie Dunagan the screechy child actor playing the scientist's toddler offspring.
Ah but the supporting players are a veritable gathering of the Gods!
Boris Karloff in his last performance as the monster mimes perfectly the brute's existential angst, Bela Lugosi gives the performance of his career as the wily hunchbacked peasant Ygor and Lionel Atwill plays it icy straight as the one armed police inspector.
If only the sequels were this good...but alas they declined in quality. Karloff passed the role of the monster on to everyone from Lon Chaney Jr to Glen Strange. Apparently Boris correctly deduced that from here on in, the monster would end up the uninteresting stooge of various other characters.
Lugosi at least seems to be having the time of his life playing the evil peasant and former grave-robber it is a performance that belies the notion that Bela was only good for playing bloodsucking aristocrats.
Currently "The Son of Frankenstein" is available as part of a DVD "Frankenstein Collection" set from Universal. If you have the scratch it is a worthwhile acquisition, there are plenty of extras plus the "Ghost of Frankenstein" (featuring another star turn from Bela Lugosi as Ygor) and the "House of Frankenstein". One can Watch the whole series come apart despite valiant efforts from reoccuring players Lone Chaney Jr., Lionel Atwill and Bela Lugosi.