For me it's comparable to Al Pacino and Robert DeNiro meeting in Heat as horror stars Vincent Price and Peter Cushing converge in Madhouse. It's a surreal and momentous moment in horror so I was compelled to share a few thoughts on the occasion.
An ageing horror star comes out of retirement only to find murder follows him everywhere he goes.

With a striking looking supporting cast both Vincent Price and Peter Cushing are excellent. Even though in their fermenting ages which is a shame, it's fitting to the story, and you can't help feel that there's irony baste over irony in Prices role of Paul Toombes, even maybe a hint of truth in the dialogue of his character. Mild-mannered Cushing as Herbert Flay unfortunately doesn't get as much screen-time as you'd like. This is certainly Price's show and he effortlessly captures the viewer with his immense presence and deep tones as much as he did 10 years earlier in The Last Man on Earth (1964).
Although reminiscent in feel of The House on Haunted Hill (1959) and The Satanic Rites of Dracula (1973) it's my no means a 'classic' but there is enough killings, spiders, old horror clips, kooky cops and good performances to keep you watching veteran editor Jim Clark's (Charade (1963), Memphis Belle (1990)) last and only horror directing contribution.
All in all, Madhouse an intriguing must see for its possible comparable look at how much real life Price was injected into Dr. Death by Ken Levison in his screenplay.