Mr. Pruitt is a retired chemist who sold his house in the suburbs after the death of his wife. His new life is very simple; he eats in the cafeteria, grows obscure herbs in his small garden, and visits his mistress, Frieda. As time passes, he makes friends with a young girl named Dorothea who wants to poison her mother for breaking her doll. Feeling disturbed at the mother’s thoughtless cruelty towards her child’s toys, Pruitt nonetheless urges Dorothea not to think about poisoning her mother. Their friendship deepens and Pruitt becomes a sympathetic ear for the girl’s troubles – until he reveals everything to Frieda, who agrees that something should be done for Dorothea. Pruitt learns from the drugstore owner’s wife that Dorothea’s mother, May Lindstrom, was accused of poisoning her dead husband, but was acquitted by the jury. Feeling troubled, he goes to speak to May about what Dorothea has been telling him. May invites him in for lunch, and she explains that ‘purity’ is more important to her than anything, and she will do whatever it takes to preserve it in her daughter. Pruitt is shown out, but not before May observes that she might have poisoned his food. A disturbed Pruitt goes home and forces himself to throw up the meal. A few days later, a gift of pears arrives at his house. The postmark is local, so he knows the sender cannot be his daughter Alice, who lives in a different state. Convinced that the pears are poisoned gifts from May, he takes them to the laboratory he used to work at and tests them for poison. Finding none, he eats the last one. A letter from May arrives after the fact, confirming that it was indeed her who sent the fruit. Determined to get revenge for the anxiety she caused in him, he gives Dorothea a vial of harmless lactose powder and tells her that it is poison. The girl is excited – she ‘poisons’ her mother, but tells her at the last second that she doesn’t want her to die. May has the powder tested, and is amused to discover that it is harmless lactose. Frieda, an extremely intuitive woman, realises that Pruitt is about to leave her; he lies to her, even though this is true. May comes over to his house, and they confess mutual admiration for each other.