AllMovie

Lucille Forrest (Frances Reid) is the wealthiest widow in Forrest Junction, but only as long as she obeys the condition in her husband's will which forbids her from reopening the investigation of her son's mysterious death. Not long after consulting with Perry Mason (Raymond Burr) to have this condition voided Lucille is accused of murdering the man she thinks is her son's killer, journalist Ralph Day (Arthur Malet). The victim died from an overdose of the same rattlesnake venom which Lucille uses as medication, meaning that Perry is going to have discredit some fairly persuasive evidence in order to expose the genuine "snake in the grass".