He paused. He had brought in his own address skilfully enough, and kept his voice sufficiently under control that no tremor betrayed a knowledge of Forbes's vital interest in any mention of that one block of flats among the multitude.
Now, for the first time, Innesmore Mansions figured as his abode, the correspondence which led to the dinner having centered in his club. But not a flicker of eyelid nor twitch of mobile lips showed the slightest concern on Forbes's part. Rather did he display at once a well-bred astonishment on hearing Theydon's concluding words.
"Do you mean detectives from Scotland Yard?" he cried.
"Yes."
Forbes smiled, and commenced filling a pipe.
"Evidently they did not want you as a principal," he said.
His tone was genial, but slightly guarded. Theydon realized that this man of great wealth and high social position had reminded himself that his guest, though armed with the best of credentials, was quite unknown to him otherwise, and that, perhaps, he had acted unwisely in inviting a stranger to his house without making some preliminary inquiry. This reversal of their roles was a conceit so ludicrous that Theydon smiled too.
At any rate, he meant now to pursue an unpleasing task, and have done with it.
"No," he said slowly. "It seems that I am the worst sort of witness in a murder case. I may have heard, I may even have seen, the person suspected of committing the crime, or, if that is going too far, the person whom the police have good reason to regard as the last who saw the poor victim alive and in ordinary conditions. But my testimony, such as it is, is so slight and inconclusive that, of itself, no one could hang a cat on it."
"Good gracious! That sounds interesting, though you have my sympathy. It must be rather distressing to be mixed up in such an affair, even indirectly."