It seemed, indeed, as though the recognition were mutual, for the man above, with an angry cry, turned suddenly away, buttoning up his overcoat with feverish fingers.

He called out to Isaac--a hurried sentence, in a language which was strange to Arnold.

There was a brief exchange of breathless words.

Arnold moved slowly away, but before he had reached the street Isaac's hand was upon his shoulder.
"One moment!" Isaac panted.

"My friend would like to know why you looked at him like that ?" Arnold did not hesitate.
"Isaac," he said, gravely, "no doubt I seemed surprised.