The asphyx.
An obssesive scientist Hugo(Robert stephens) takes pictures of dead bodies and discovers the secret of immortlity is to trap a spirit called a asphyx that appears at the moment of someones death.
A very original horror film indeed that is quite fascinating and creepy and morbid, with good period settings in the Hammer film style.
And extremely well acted too by stephens in the lead role, and co-stars Robert Powell as the son in law and Jane laportaire as Hugo's daughter who has a bad experince with a guillotine.
a classy and intelligent film that is a good watch indeed, with great special effects for the time with a creepy looking asphyx. 80 out of 100.