“But you wanted to go through it all from the beginning. Well, the beginning, I think—if Inspector Craddock agrees with me—was when Charlotte Blacklock, a pretty, lighthearted affectionate girl, developed that enlargement of the thryoid gland that’s called a goitre. It ruined her life, because she was a very sensitive girl. A girl, too, who had always set a lot of stress on her personal appearance. And girls just at that age in their teens are particularly sensitive about themselves. If she’d had a mother, or a reasonable father, I don’t think she would have got into the morbid state she undoubtedly did get into. She had no one, you see, to take her out of herself, and force her to see people and lead a normal life and not think too much about her infirmity. And, of course, in a different household, she might have been sent for an operation many years earlier.

“But Dr. Blacklock, I think, was an old-fashioned, narrow-minded, tyrannical and obstinate man. He didn’t believe in these operations. Charlotte must take it from him that nothing could be done—apart from dosage with iodine and other drugs. Charlotte did take it from him, and I think her sister also placed more faith in Dr. Blacklock’s powers as a physician than he deserved.

“Charlotte was devoted to her father in a rather weak and soppy way. She thought, definitely, that her father knew best. But she shut herself up more and more as the goitre became larger and more unsightly, and refused to see people. She was actually a kindly affectionate creature.”

“That’s an odd description of a murderess,” said Edmund.

“I don’t know that it is,” said Miss Marple. “Weak and kindly people are often very treacherous. And if they’ve got a grudge against life it saps the little moral strength that they may possess.

“Letitia Blacklock, of course, had quite a different personality. Inspector Craddock told me that Belle Goedler described her as really good—and I think Letitia was good. She was a woman of great integrity who found—as she put it herself—a great difficulty in understanding how people couldn’t see what was dishonest. Letitia Blacklock, however tempted, would never have contemplated any kind of fraud for a moment.

“Letitia was devoted to her sister. She wrote her long accounts of everything that happened in an effort to keep her sister in touch with life. She was worried by the morbid state Charlotte was getting into.

“Finally Dr. Blacklock died. Letitia, without hesitation, threw up her position with Randall Goedler and devoted herself to Charlotte. She took her to Switzerland, to consult authorities there on the possibility of operating. It had been left very late—but as we know the operation was successful. The deformity was gone—and the scar this operation had left was easily hidden by a choker of pearls or beads.