Eight guests are invited to dinner at a mysterious house by an unnamed host. The guests all have reason to hate one of the other members so things are a bit fractious. Then a voice from the radio tells them they will be murdered one by one unless they manage to outwit their host, the ninth guest. To underscore the threat they can't leave as he has had the gates connected to the mains, plus various other traps...
Naturally the other guests do not take to this well and start accusing each other of being this ninth guest. The story moves on from there as the guests die off in various ways. It does sound a bit Agatha Christie, though this film (and the original story) predates And Then There Were None / Ten Little Indians (1945) (1965) (1972) by a number of years...
Donald Cook and Genevieve Tobin star as two of the guests, who manage to work out their mutual antagonism as they help solve the mystery of who is the ninth guest. The story is a little complicated with a lot of red herrings (maybe a few too many) but an enjoyable watch.
