The story begins with a lawyer confirming that all members of the Greene family are present at their mother’s deathbed. This is due to a stipulation in their deceased father's will: if they don't reside together for fifteen years following his passing, they receive nothing. Predictably, there’s considerable friction among them, so when one of them turns up dead, it isn’t particularly surprising. The police—specifically Eugene Pallette as "Sgt. Heath"—arrive and bring in detective "Philo Vance" (William Powell) to assist. He soon realizes that any of the family members could be responsible. However, the killer doesn't stop with just one victim; as more family members die, the investigators must hurry to ensure they aren’t all eliminated. The film is quite theatrical in its presentation, but it moves along at a rapid pace and features several characters—most notably the ailing and irritable mother (Gertrude Norman)—who help propel the investigation toward its somewhat surprising end. It feels like a blend of other "Dark House" narratives, though Powell and Pallette perform admirably.

Source on TMDB