This is one of the most memorable movies from the 70's. I saw this when I was about 7 years old at 2 am in the morning and I remembered it for years after! David Hartman and Don Knotts maintain levity as they investigate a mystery in a creepy old mansion. In search of a missing billionaire, the detectives embark on a journey through the mysterious and colorful mansion which chimes of a baby crying. Is the baby real and stuck in the ventilation system or is it just a prank? Watch the mysteries unfold as Don Knotts bumbles and stumbles around in his typical skittish fashion. Appreantly, this gem of a little-known movie was themed after an earlier radio series of the same title. I loved it and wish it would be released officially!