Tommy interrupted these reminiscences.

"This kitchen of yours? Does anyone else use it except you and Miss Chilcott?"

"Hannah clears up there. And she boils the kettle there for our early morning tea."

"Thank you, Miss Logan," said Tommy. "There is nothing more I want to ask you at present. I hope we haven't tired you too much."

He left the room and went down the stairs, frowning to himself.

"There is something here, my dear Mr. Ricardo, that I do not understand."

"I hate this house," said Tuppence with a shiver. "Let's go for a good long walk and try to think things out."

Tommy complied and they set out. First they left the cocktail glass at the doctor's house and then set off for a good tramp across country discussing the case as they did so.

"It makes it easier somehow if one plays the fool," said Tommy. "All this Hanaud business. I suppose some people would think I didn't care. But I do, most awfully. I feel that somehow or other we ought to have prevented this."

"I think that's foolish of you," said Tuppence. "It is not as though we had advised Lois Hargreaves not to go to Scotland Yard or anything like that. Nothing would have induced her to bring the police into the matter. If she hadn't come to us, she would have done nothing at all."

"And the result would have been the same. Yes, you are right, Tuppence. It's morbid to reproach oneself over something one couldn't help. What I would like to do is to make good now."

"And that's not going to be easy."

"No, it isn't. There are so many possibilities, and yet all of them seem wild and improbable. Supposing Dennis Radclyffe put the poison in the sandwiches. He knew he would be out to tea. That seems fairly plain sailing."

"Yes," said Tuppence, "that's all right so far. Then we can put against that the fact that he was poisoned himself-so that seems to rule him out. There is one person we mustn't forget-and that is Hannah."

"Hannah?"

"People do all sorts of queer things when they have religious mania."

"She is pretty far gone with it too," said Tommy. "You ought to drop a word to Dr. Burton about it."

"It must have come on very rapidly," said Tuppence. "That is if we go by what Miss Logan said."

"I believe religious mania does," said Tommy. "I mean, you go on singing hymns in your bedroom with the door open for years, and then you go suddenly right over the line and become violent."

"There is certainly more evidence against Hannah than against anybody else," said Tuppence thoughtfully, "and yet I have an idea-" She stopped.

"Yes?" said Tommy encouragingly.

"It is not really an idea. I suppose it is just a prejudice."

"A prejudice against someone?"

Tuppence nodded.

"Tommy-did you like Mary Chilcott?"

Tommy considered.

"Yes, I think I did. She struck me as extremely capable and businesslike-perhaps a shade too much so-but very reliable."

"You didn't think it was odd that she didn't seem more upset?"

"Well, in a way that is a point in her favor. I mean, if she had done anything, she would make a point of being upset-lay it on rather thick."

"I suppose so," said Tuppence. "And anyway there doesn't seem to be any motive in her case. One doesn't see what good this wholesale slaughter can do her."

"I suppose none of the servants are concerned?"

"It doesn't seem likely. They seem a quiet reliable lot. I wonder what Esther Quant, the parlormaid, was like."

"You mean, that if she was young and good-looking there was a chance that she was mixed up in it some way."

"That is what I mean." Tuppence sighed. "It is all very discouraging."

"Well, I suppose the police will get down to it all right," said Tommy.

"Probably. I should like it to be us. By the way, did you notice a lot of small red dots on Miss Logan's arm?"

"I don't think I did. What about them?"

"They looked as though they were made by a hypodermic syringe," said Tuppence.

"Probably Dr. Burton gave her a hypodermic injection of some kind."

"Oh, very likely. But he wouldn't give her about forty."

"The cocaine habit," suggested Tommy helpfully.

"I thought of that," said Tuppence, "but her eyes were all right. You would see at once if it was cocaine or morphia. Besides she doesn't look that sort of old lady."

"Most respectable and God fearing" agreed Tommy.

"It is all very difficult," said Tuppence. "We have talked and talked and we don't seem any nearer now than we were. Don't let's forget to call at the doctor's on our way home."

The doctor's door was opened by a lanky boy of about fifteen.

"Mr. Blunt?" he inquired. "Yes, the doctor is out but he left a note for you in case you should call."

He handed them the note in question and Tommy tore it open.

"Dear Mr. Blunt,

There is reason to believe that the poison employed

was Ricin, a vegetable toxalbumose of tremendous

potency. Please keep this to yourself for the present."

Tommy let the note drop, but picked it up quickly.

"Ricin," he murmured. "Know anything about it, Tuppence? You used to be rather well up in these things."

"Ricin," said Tuppence, thoughtfully. "You get it out of Castor Oil, I believe."

"I never did take kindly to Castor Oil," said Tommy. "I am more set against it than ever now."

"The oil's all right. You get Ricin from the seeds of the Castor Oil plant. I believe I saw some Castor Oil plants in the garden this morning-big things with glossy leaves."

"You mean that someone extracted the stuff on the premises. Could Hannah do such a thing?

Tuppence shook her head.

"Doesn't seem likely. She wouldn't know enough."

Suddenly Tommy gave an exclamation.

"That book. Have I got it in my pocket still? Yes." He took it out, and turned over the leaves vehemently. "I thought so. Here's the page it was open at this morning. Do you see, Tuppence? Ricin!"

Tuppence seized the book from him.

"Can you make head or tail of it? I can't."

"It's clear enough to me," said Tuppence. She walked along, reading busily, with one hand on Tommy's arm to steer herself. Presently she shut the book with a bang. They were just approaching the house again.

"Tommy, will you leave this to me? Just for once, you see, I am the bull that has been more than twenty minutes in the arena."

Tommy nodded.

"You shall be the Captain of the Ship, Tuppence," he said gravely. "We've got to get to the bottom of this."

"First of all," said Tuppence as they entered the house, "I must ask Miss Logan one more question."

She ran upstairs. Tommy followed her. She rapped sharply on the old lady's door, and went in.

"Is that you, my dear?" said Miss Logan. "You know you are much too young and pretty to be a detective. Have you found out anything?"

"Yes," said Tuppence. "I have."

Miss Logan looked at her questioningly.

"I don't know about being pretty," went on Tuppence, "but being young, I happened to work in a hospital during the War. I know something about serum therapeutics. I happen to know that when Ricin is injected in small doses hypodermically immunity is produced, antiricin is formed. That fact paced the way for the foundation of serum therapeutics. You knew that, Miss Logan. You injected Ricin for some time hypodermically into yourself. Then you let yourself be poisoned with the rest. You helped your father in his work, and you knew all about Ricin and how to obtain it and extract it from the seeds. You chose a day when Dennis Radclyffe was out for tea. It wouldn't do for him to be poisoned at the same time-he might die before Lois Hargreaves. So long as she died first, he inherited her money, and at his death it passes to you, his next of kin. You remember, you told us this morning that his father was your first cousin."

The old lady stared at Tuppence with baleful eyes.

Suddenly a wild figure burst in from the adjoining room. It was Hannah. In her hand she held a lighted torch which she waved frantically.

"Truth has been spoken. That is the wicked one. I saw her reading the book, and smiling to herself and I knew. I found the book and the page-but it said nothing to me. But the voice of the Lord spoke to me. She hated my mistress, her ladyship. She was always jealous and envious. She hated my own sweet Miss Lois. But the wicked shall perish, the fire of the Lord shall consume them."

Waving her torch she sprang forward to the bed.

A cry arose from the old lady.

"Take her away-take her away. It's true-but take her away."

Tuppence flung herself upon Hannah, but the woman managed to set fire to the curtains of the bed before Tuppence could get the torch from her and stamp on it. Tommy, however, had rushed in from the landing outside. He tore down the bed hangings and managed to stifle the flames with a rug. Then he rushed to Tuppence's assistance and between them they subdued Hannah just as Dr. Burton came hurrying in.

A very few words sufficed to put him au courant of the situation.

He hurried to the bedside, lifted Miss Logan's hand, then uttered a sharp exclamation.

"The shock of fire has been too much for her. She's dead. Perhaps it is as well under the circumstances."

He paused and then added, "There was Ricin in the cocktail glass as well."

"It's the best thing that could have happened," said Tommy when they had relinquished Hannah to the doctor's care, and were alone together. "Tuppence, you were simply marvellous."

"There wasn't much Hanaud about it," said Tuppence.

"It was too serious for play acting. I still can't bear to think of that girl. I won't think of her. But, as I said before, you were marvellous. The honors are with you. To use a familiar quotation, 'It is a great advantage to be intelligent and not to look it.' "

"Tommy," said Tuppence. "You're a beast."