Murder in the Blue Room (1944)

This starts off quite spookily with a masked man draped in a sheet welcoming the guests to an haunted mansion for a good old game of mysterious "Cleudo". Of course he doesn't know that at the start of the evening, but given we have loads of people and an old rickety building, it's a bit of a "dead" cert, eh? Writer "Steve" (Donald Cook) who specialises in mysteries is charged with investigating the rumoured haunting of this house's long-sealed Blue Room by the ghost of the father of their host "Nan" (Anne Gwynne). When one of their number decides to sleep in that room, and then goes missing, "Steve" and "Anne" have to race police "Insp. McDonald" (Regis Toomey) to get to the bottom of things. Now to the drawback. The singing. Yes, there are two or three little numbers thrown in as the annoyingly jolly "Jazzybelles" do a bit of musical sleuthing of their own delivering some lyrics that would make "cat, sat and mat" sound like Ivor Novello award winning stuff. Overlook those interludes, though, and it's actually quite a fun, throwaway, mystery that presents a competent cast and you'll probably enjoy it for an hour though never remember it afterwards.