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.