What a Christmas! It’s Jack and Jill’s turn to be host, whilst their daughter is due to have her baby and their son-in-law’s parents arrive for the holiday. Jill’s close friend, TV actor Laura and her dipsomaniac husband, Harry, are also guests. Jill learns that Laura’s marriage is not all it seems, but when, in the middle of the night, Jill falls in trying to reach the phone, breaking a leg, that’s only the start of the nightmare. The plot ducks and weaves to the surprise ending.