Dr. Phibes had supposedly died many years prior, but in the mid-1920's why he the only suspect is a serious of very strange deaths. Dr. Phibes, if he's still alive is gaining revenge on the doctors who let his darling wife die. But Dr. Phibes is killing in a meaningful way, by using the 10 curses visited upon the Pharaoh in the Bible: from frogs to locusts to rats to death of the first born son. Inspector Trout and Sergeant Schenley are on the case but seem to be too late in every case to stop the deaths from happening.
Extravagant sets and ingenious deaths, Dr. Phibes is the precursor to films like Seven, where serial killers use religion as their trademark kill. The film is serious but also filled with a wry wit which makes it much more intriguing to watch than had it tried to go be a straight horror film.