Is Magistrate Simon Cordier slowly losing his mind or is he being possessed by a darker, more sinister force? This is the question that is explored in Diary of a Madman. Vincent Price [The Fly, House of Wax] is wonderful as Cordier. Although Price can sometimes be guilty of over-the-top performances, his work in Diary is subtle and nuanced. This is definitely Price's show and everyone else is along for the ride.
The screenplay for Diary is from veteran writer Robert E. Kent [Zombies on Broadway, Twice-Told Tales] who adapted several of the short stories of French writer Guy de Maupassant. He gives Price plenty of great material to work with and the story is classic thriller material. Director Reginald Le Borg [The Mummy's Ghost, The Black Sleep] is no stranger to the director's chair and does an excellent job of bringing this story to life. The only bad choice in this film is this way the Horla (the evil entity in question) is portrayed. The green light bar over Price's eyes and the "voice in an echo chamber" come across as cheesy other than menacing. With a different choice, Diary would have been even more powerful and dramatic.
So, if you like thrillers and are a fan of Vincent Prince, then I highly recommend Diary of a Madman. It is one of Price's most overlooked and underappreciated films. Don't miss it!
RATING: Very Good.
For more info check out the film's entry in IMDB.