“Exactly! Moreover he offered this information,” Alleyn pointed out. “One must remember the circumstances. The scene, real or simulated, reached its climax as the train drew up and stopped. The blind was released as the woman fell against it. And the man, not necessarily Oberon or Baradi, you know, saw other windows — those of the train.”

“So knowing Monsieur must have been in the train and awake, since he was to alight at Roqueville, this blasphemer produces his lies.”

“It might well be so. M. Dupont and I both incline to think so. Now, you see, don’t you, that if murder was done in that room in the early hours of this morning, we have great cause to revisit the Château. Not only to arrest a killer but to discover why he killed. Not only to arrest a purveyor of drugs who has caused many deaths but to discover his associates. And not only for these reasons but also to learn, if we can, what happens in the locked room on Thursday nights. For all these reasons, Raoul, it seems imperative that we visit the Château.”

“Well, Monsieur.”

“Two courses suggest themselves. I may return openly to enquire after the health of Mademoiselle Truebody. If I do this I shall have to admit that Ricky has been found.”

“They will have learned as much from the man Callard, Monsieur.”

“I am not so sure. This afternoon M. Dupont ordered that all outward calls from the factory should be blocked at central and that the Château should be cut off. At the Château they will be extremely anxious to avoid any sign that they are in touch with the factory. They will, of course, question Teresa, to whom we must give instructions. If I pursue our first course I shall tell the story of the finding of Ricky to Mr. Oberon and his guests and I shall utter many maledictions against Callard as a child-kidnapper. And, having seen Miss Truebody, I must appear to go away and somehow or another remain. I’ve no idea how this can be done. Perhaps, if one had a colleague within the place one might manage it. The alternative is for me, and you, Raoul, to go secretly to the Château. To do this we would again need a colleague who would admit and conceal us.”

Raoul put his head on one side with the air of a collector examining a doubtful treasure. “Monsieur refers, of course, to Teresa,” he said.

“I do.”

“Teresa,” Raoul continued anxiously, “has not displayed herself to advantage this afternoon. She was bouleversée and therefore behaved foolishly. Nevertheless, she is normally a girl of spirit. She is also at the present time desirous of reestablishing herself in my heart. Possibly I have been too lenient with her but one inclines to leniency where one’s affections are engaged. I have, as Monsieur knows, forbidden her return to this temple of shame. Nevertheless, where the cause is just and with the protection of Our Lady of Paysdoux (about whose patronage Teresa is so unbecomingly cocksure), there can be no sin.”

“I take it,” Alleyn said, “that you withdraw your objection?”

“Yes, Monsieur. Not without misgivings because Teresa is dear to me and, say what you like, it is no place for one’s girl.”

“Judging by the lacerations in Georges Mattel’s face, Teresa is able to defend herself on occasion.”

“True,” Raoul agreed, cheering up. “She has enterprise.”

“Suppose we talk to her about it?”

“I will produce her.”

Raoul went out to the kitchen.

“Hallo, you two,” Alleyn said.

“Hallo, yourself,” Troy said.

“Daddy, this is a lavish book. I can read it better than Mummy.”

“Don’t buck,” Alleyn said automatically.

“Have you sent Raoul to get that nanny-person? Teresa?”

“Yes.”

“Why?”

“We’ve got a job for her.”

“Not minding me?”

“No, no. Nothing to do with you, old boy.”

“Well, good, anyway,” said Ricky returning to his book.

Raoul came back with Teresa, who now wore an apron and seemed to be in remarkably high spirits. On Alleyn’s invitation she sat down using, however, the very edge of her chair. Alleyn told her briefly what he wanted her to do. Raoul folded his arms and scowled thoughtfully at the tablecloth.

“You see, Teresa,” Alleyn said, “these are bad men and also unfortunately extremely clever men. They think they’ve made a fool of you as they have of a great many other silly girls. The thing is — are you ready to help Raoul and me and the police of your own country to put a stop to their wickedness?”

“Ah, yes, Monsieur,” said Teresa cheerfully. “I now perceive my duty and with the help of Raoul and the holy saints, dedicate myself to the cause.”

“Good. Do you think you can keep your head and behave sensibly and with address if an emergency should arise?”

Teresa gazed at him and said that she thought she could.

“Very well. Now, tell me: were you on duty last evening?”

“Yes, Monsieur. During the dinner I helped the housemaids go round the bedrooms and then I worked in the kitchen.”

“Was there a party?”

“A party? Well, Monsieur, there was the new guest, Mlle. Wells, who is an actress. And after dinner there was a gathering of all the guests in the private apartments of M. Oberon. I know this because I heard the butler say that Monsieur wished it made ready for a special welcome for Mlle. Wells. And this morning,” said Teresa, looking prim, “Jeanne Barre, who is an under-housemaid, said that Mlle. Locke, the English noblewoman, must have taken too much wine because her door was locked with a notice not to disturb and this is always a sign she has been indiscreet.”

“I see. Tell me, Teresa: have you ever seen into the room that is only opened on Thursday night?”

“Yes, Monsieur. On Thursday morning I dust this room and on Fridays it is my duty to clean it.”

“Where is it exactly?”

“It is down the stairs, three flights, from the vestibule, and beneath the library. It is next to the private apartments of M. Oberon.”

“Has it many windows?”

“It has no windows, Monsieur. It is in a very old part of the Château.”

“And M. Oberon’s rooms?”

“Oh, yes, Monsieur. The salon has a window which is covered always by a white blind with a painting of the sun because Monsieur dislikes a brilliant light, so it is always closed. But Monsieur has nevertheless a great lamp fashioned like the sun and many strange ornaments and a strange wheel which Monsieur treasures and a magnificent bed and in the salon a rich divan,” said Teresa, warming to her subject, “and an enormous mirror where—” There she stopped short and blushed.

“Continue,” Raoul ordered, with a face of thunder.

“Where once when I took in petit déjeuner I saw Monsieur contemplating himself in a state of nature.”

Alleyn, with an eye on Raoul, said hurriedly, “Will you describe the room that you clean?”

Raoul reached across the table and moved his forefinger to and fro in front of his beloved’s nose. “Choose your words, my treasure,” he urged. “Invent nothing. Accuracy is all.”

“Yes, indeed it is,” said Alleyn heartily.

Thus warned, Teresa looked self-consciously at her folded hands and with a slightly sanctimonious air began her recital.

“If you please, Monsieur, it is a large room and at first I thought perhaps it was a chapel.”

“A chapel?” Alleyn exclaimed. Raoul made a composite noise suggestive of angry incredulity.

“Yes, Monsieur. I thought perhaps it was reserved for the private devotions of M. Oberon and his friends. Because at one side is a raised place with a table like the holy altar, covered in a cloth which is woven in a rich pattern with gold and silver and jewels. But although one saw the holy cross, there were other things in the pattern that one does not see in altar cloths.”

“The hoof prints of anathema!” Raoul ejaculated.

“Go on, Teresa,” said Alleyn.

“And on the table there was something that was also covered with an embroidered cloth.”