Miss Climpson had here no doubt what the priest’s ruling would be. “You need not go out of your way to betray your friend’s confidence. Keep silent if you can, but if you speak you must speak the truth. You must tell your friend that she is not to expect any more lying from you. She is entitled to ask for secrecy—no more.”

So far, so good. But there was a further problem.

“Ought I to connive at her doing what is wrong?”—and then a sort of explanatory aside—“the man in South Audley Street.”

This was a little mysterious. . . No!—on the contrary, it explained the whole mystery, jealousy, quarrel and all.

In those weeks of April and May, when Mary Whittaker had been supposed to be all the time in Kent with Vera Findlater, she had been going up to London. And Vera had promised to say that Mary was with her the whole time. And the visits to London had to do with a man in South Audley Street, and there was something sinful about it. That probably meant a love-affair. Miss Climpson pursed her lips virtuously, but she was more surprised than shocked. Mary Whittaker! she would never have suspected it of her, somehow. But it so explained the jealousy and the quarrel—the sense of desertion. But how had Vera found out? Had Mary Whittaker confided in her?—No; that sentence again, under the heading “Jealousy”—what was it—“following M. W to London.” She had followed then, and seen. And then, at some moment, she had burst out with her knowledge—reproached her friend. Yet this expedition to London must have happened before her own conversation with Vera Findlater, and the girl had then seemed so sure of Mary’s affection. Or had it been that she was trying to persuade herself, with determined self-deception, that there was “nothing in” this business about the man? Probably. And probably some brutality of Mary’s had brought all the miserable suspicions boiling to the surface, vocal, reproachful and furious. And so they had gone on to the row and the break.

“Queer,” thought Miss Climpson, “that Vera has never come and told me about her trouble. But perhaps she is ashamed, poor child. I haven’t seen her for nearly a week. I think I’ll call and see her and perhaps she’ll tell me all about it. In which case”—cried Miss Climpson’s conscience, suddenly emerging with a bright and beaming smile from under the buffets of the enemy—“in which case I shall know the whole history of it legitimately and can quite honourably tell Lord Peter about it.”

The next day—which was the Friday—she woke, however, with an unpleasant ache in the conscience. The paper—still tucked into the office-book—worried her. She went round early to Vera Findlater’s house, only to hear that she was staying with Miss Whittaker. “Then I suppose they’ve made it up,” she said. She did not want to see Mary Whittaker, whether her secret was murder or mere immorality; but she was tormented by the desire to clear up the matter of the alibi for Lord Peter.

In Wellington Avenue she was told that the two girls had gone away on the Monday and had not yet returned. She tried to reassure the maid, but her own heart misgave her. Without any real reason, she was uneasy. She went round to the church and said her prayers, but her mind was not on what she was saying. On an impulse, she caught Mr. Tredgold as he pottered in and out of the Sacristy, and asked if she might come the next evening to lay a case of conscience before him. So far, so good, and she felt that a “good walk” might help to clear the cob-webs from her brain.

So she started off, missing Lord Peter by a quarter of an hour, and took the train to Guildford and then walked and had lunch in a wayside tea-shop and walked back into Guildford and so came home, where she learnt that “Mr. Parker and ever so many gentlemen had been asking for her all day, and what a dreadful thing, miss, here was Miss Whittaker and Miss Findlater disappeared and the police out looking for them, and them motor-cars was such dangerous things, miss, wasn’t they? It was to be hoped there wasn’t an accident.”

And into Miss Climpson’s mind there came, like an inspiration, the words, “South Audley Street.”