premise: Things Happen at Night is a 1947 British supernatural ghost comedy film directed by Francis Searle and starring Gordon Harker, Alfred Drayton, Robertson Hare and Gwynneth Vaughan. The film is based upon a stage play, "The Poltergeist", by Frank Harvey Jnr.
hypothesis: Things Happen at Night and "The Poltergeist" share the same total runtime. 
reason: The context mentions that Things Happen at Night is based off "The Poltergeist" but the context makes no mention of how long the film is nor does it say how long the stage play is. Therefore, we cannot know if they share the same runtime. The system might have been confused since the context mentions that one was based off of the other.