Coquenil walked across the square to the cathedral, moving slowly, thinking over the events of the night.  They had crossed the track of the assassin, that was sure, but they had discovered nothing that could help in his capture except the fact of the long little finger.  The man had left absolutely nothing in his room at the hotel (this they verified with the help of false keys), and had never returned after the night of the crime, although he had taken the room for a month, and paid the rent in advance.  He had made two visits to this room, one at about three in the afternoon of the fatal day, when he spent an hour there, and entered Kittredge’s room, no doubt, for the boots and the pistol; the other visit he made the same night when he tried to return the boots and was prevented from doing so.  How he must have cursed that little photographer!

As to the assassin’s personal appearance, there was a startling difference of opinion between the hotel doorkeeper and the garcon, both of whom saw him and spoke to him.  The one declared he had light hair and a beard, the other that he had dark hair and no beard; the one thought he was a Frenchman, the other was sure he was a foreigner.  Evidently the man was disguised either coming or going, so this testimony was practically worthless.

Despite all this, Coquenil was pleased and confident as he rang the night bell at the archbishop’s house beside the cathedral, for he had one precious clew, he had the indication of this extraordinarily long little finger, and he did not believe that in all France there were two men with hands like that.  And he knew there was one such man, for Alice had seen him.  Where had she seen him?  She said she had often noticed his long little finger, so she must often have been close enough to him to observe such a small peculiarity.  But Alice went about very little, she had few friends, and all of them must be known to the Bonnetons.  It ought to be easy to get from the sacristan this information which the girl herself might withhold.  Hence this nocturnal visit to Notre Dame—­it was of the utmost importance that Coquenil have an immediate talk with Papa Bonneton.

And presently, after a sleepy salutation from the archbishop’s servant, and a brief explanation, M. Paul was shown through a stone passageway that connects the church with the house, and on pushing open a wide door covered with red velvet, he found himself alone in Notre Dame, alone in utter darkness save for a point of red light on the shadowy altar before the Blessed Sacrament.

As he stood uncertain which way to turn, the detective heard a step and a low growl, and peering among the arches of the choir he saw a lantern advancing, then a figure holding the lantern, then another crouching figure moving before the lantern.  Then he recognized Caesar.

“Phee-et, phee-et!” he whistled softly, and with a start and a glad rush, the dog came bounding to his master, while the sacristan stared in alarm.