The newcomer was a youngish man, a musician, who had just come from a concert and was on his way to the club at the end of the street.  Probably, had he been a journalist, his curiosity would have been greater than his incredulity.  As it was, however, he gazed at Tavernake, for a moment, blankly.

“Look here,” he said, “this doesn’t sound a very likely story of yours, you know.”

“I don’t care whether it’s likely or not,” Tavernake answered hotly; “it’s true!  The knife’s somewhere in the road there—­it fell up against the railings.”

They crossed the road together and searched.  There were no signs of the weapon.  Tavernake peered over the railings.

“When my friend struck the other man and twisted him over,” he explained, “the knife seemed to fly up into the air; it might even have reached the gardens.”

His companion turned slowly away.

“Well, it’s no use looking down there for it,” he remarked.  “We might try the door, if you like.”

They leaned their weight against it, hammered at the panels, and waited.  The door was fast closed and no reply came.  The musician shrugged his shoulders and prepared to depart, after one more glance at Tavernake, half suspicious, half questioning.

“If you think it worth while,” he said, “you had better fetch the police, perhaps.  If you take my advice, though, I think I should go home and forget all about it.”

He passed on, leaving Tavernake speechless.  The idea that people might not believe his story had never seriously occurred to him.  Yet all of a sudden he began to doubt it himself.  He stepped back into the road and looked up at the windows of the house —­ dark, uncurtained, revealing no sign of life or habitation.  Had he really taken that walk with Pritchard, stood on this spot with him only a minute or two ago?  Then he picked up the police whistle and he had no longer any doubts.  The whole scene was before him again, more vividly than ever.  Even at this moment, Pritchard might be in need of help!

He turned and walked sharply to the corner of the Terrace, finding himself almost immediately face to face with a policeman.

“You must come into this house with me at once!” Tavernake exclaimed, pointing backwards.  “A friend of mine was attacked here just now; a man tried to stab him.  They are both in that house.  The man ran away and my friend followed him.  The door is closed and no one answers.”

The constable looked at Tavernake very much as the musician had done.

“Do either of them live there, sir?” he asked.

“How should I know!” Tavernake answered.  “The man sprang upon my friend from behind.  He had a knife in his hand—­I saw it.  My friend threw him over and he escaped into that house.  They are both there now.

“Which house is it, sir?” the policeman inquired.

They were standing almost in front of it.  The gate was open and Tavernake beat against the panels with the flat of his hand.  Then, with a cry of triumph, he stooped down and picked something up from a crack in the flagged stones.