Altogether it was a pleasing picture, and Coquenil’s interest was heightened when he overheard a passing couple say that these were the guests of no less a person than the Duke of Montreuil, whose lavish entertainments were the talk of Paris.  There he was, on the break, this favorite of fortune!  What a brilliant figure of a man!  Famous as a sportsman, enormously rich, popular in society, at the head of vast industrial enterprises, and known to have almost controlling power in affairs of state!

“Never mind, old sport, it takes all kinds of people to make up the world.  Now then, jump!”

So they went on, playing together, master and dog, and were passing around through the woods on the far side of the coaching party, when, suddenly, Caesar ceased his romping and began to nose the ground excitedly.  Then, running to his master, he stood with eager eyes, as if urging some pursuit.

The detective observed the dog in surprise.  Was this some foolish whim to follow a squirrel or a rabbit?  It wasn’t like Caesar.

“Come, come,” he reasoned with friendly chiding, “don’t be a baby.”

Caesar growled in vigorous protest, and darting away, began circling the ground before him, back and forth, in widening curves, as Coquenil had taught him.

“Have you found something—­sure?”

The animal barked joyously.

M. Paul was puzzled.  Evidently there was a scent here, but what scent?  He had made no experiments with Caesar since the night of the crime, when the dog had taken the scent of the pistol and found the alleyway footprints.  But that was ten days ago; the dog could not still be on that same scent.  Impossible!  Yet he was on some scent, and very eagerly.  Coquenil had never seen him more impatient for permission to be off.  Could a dog remember a scent for ten days?

“After all, what harm can it do?” reflected the detective, becoming interested in his turn.  Then, deciding quickly, he gave the word, “Cherche!” and instantly the dog was away.

“He means business,” muttered M. Paul, hurrying after him.

On through the woods went Caesar, nose down, tail rigid, following the scent, moving carefully among the trees, and once or twice losing the trail, but quickly finding it again, and, presently, as he reached more open ground, running ahead swiftly, straight toward the coaching party.

In a flash Coquenil realized the danger and called loudly to the dog, but the distance was too great, and his voice was drowned by the cries of ladies on the break, who, seeing the bounding animal, screamed their fright.  And no wonder, for this powerful, close-clipped creature, in his sudden rush looked like some formidable beast of prey; even the men started up in alarm.

“Caesar!” shouted M. Paul, but it was too late.  The dog was flying full at the break, eyes fixed, body tense; now he was gathering strength to spring, and now, with a splendid effort, he was actually hurling himself through the air, when among the confused figures on the coach a man leaned forward suddenly, and something flashed in his hand.  There was a feather of smoke, a sharp report, and then, with a stab of pain, Coquenil saw Caesar fall back to the ground and lie still.