The family doctor, fearful that his friend's slow son had been the cause of his mother's and now her sister (his proposed step-mother's) deaths by poison, quickly becomes suspicious of the boy's caretaker. Cousin to his father, and disappointed in her love for him, she had murdered both her rivals and intended to blackmail the father by blaming the son. The boy awakens from his years' long stupour and proves her guilt. (PB)