Doctor Dormann had behaved very strangely.

He was the first person who made the terrible discovery of the death. When he came to the house, on his evening visit to his patient, Mr. Keller was in the room. Half an hour before, Mrs. Wagner had spoken to him. Seeing a slight movement of her lips, he had bent over her, and had just succeeded in hearing her few last words, "Be kind to Jack." Her eyelids dropped wearily, after the struggle to speak. Mr. Keller and the servant in attendance both supposed that she had fallen asleep. The doctor\'s examination was not only prolonged beyond all customary limits of time in such cases—it was the examination (judging by certain expressions which escaped him) of a man who seemed to be unwilling to trust his own experience. The new nurse arrived, before he had definitely expressed his opinion; and the servant was instructed to keep her waiting downstairs. In expectation of the doctor\'s report, Mr. Keller remained in the bedroom. Doctor Dormann might not have noticed this circumstance, or might not have cared to conceal what was passing in his mind. In either case, when he spoke at last, he expressed himself in these extraordinary terms:—

"The second suspicious illness in this house! And the second incomprehensible end to it!"

Mr. Keller at once stepped forward, and showed himself.

"Did you mean me to hear what you have just said?" he asked.

The doctor looked at him gravely and sadly. "I must speak to you privately, Mr. Keller. Before we leave the room, permit me to send for the nurse. You may safely trust her to perform the last sad duties."

Mr. Keller started. "Good God!" he exclaimed, "is Mrs. Wagner dead?"

"To my astonishment, she is dead." He laid a strong emphasis on the first part of his reply.

The nurse having received her instructions, Mr. Keller led the way to his private room. "In my responsible position," he said, "I may not unreasonably expect that you will explain yourself without reserve."

"On such a serious matter as this," Doctor Dormann answered, "it is my duty to speak without reserve. The person whom you employ to direct the funeral will ask you for the customary certificate. I refuse to give it."

This startling declaration roused a feeling of anger, rather than of alarm, in a man of Mr. Keller\'s resolute character. "For what reason do you refuse?" he asked sternly.

"I am not satisfied, sir, that Mrs. Wagner has died a natural death. My experience entirely fails to account for the suddenly fatal termination of the disease, in the case of a patient of her healthy constitution, and at her comparatively early age."

"Doctor Dormann, do you suspect there is a poisoner in my house?"

"In plain words, I do."

"In plain words on my side, I ask why?"

"I have already given you my reason."

"Is your experience infallible? Have you never made............