patrons, or possibly its proprietor. If Nick had had no business on his
hands he would have followed that carriage.

As it happened, however, the man for whom the detective was watching
appeared at that moment.

Nick was obliged to follow him, but he knew that he would not have to go
far, for Chick was waiting on Sixth avenue, and it was in that direction
that the thief turned.

So it happened that within ten minutes Nick was able to turn this case
over to his famous assistant, and return to clear up the mystery of the
queer incident which he had chanced to observe.

Nick would not have been surprised to find the restaurant in an uproar,
but it was as quiet as usual. He entered by the side door, ascended a
flight of stairs, and came to a sort of office with a desk and a
register.

It was the custom of the place that guests should put down their names
as in a hotel before being assigned to a private dining-room.

There was nobody in sight.

The hall led toward the front of the building, and there were three
rooms on the side of it toward the street.

All the doors were open and the rooms were empty. Nick glanced into
these rooms, and then turned toward the desk. As he did so he saw a
waiter coming down the stairs from the floor above.