Tournefort was after him in a trice.  When he reached the corner of the street he saw Rateau, at the further end of it, take a sudden sharp turn to the right.  But not before he had very obviously spied his pursuer, for at that moment his entire demeanour changed.  An air of furtive anxiety was expressed in his whole attitude.  Even at that distance Tournefort could see him clutching his bulky parcel close to his chest.

After that the pursuit became closer and hotter.  Rateau was in and out of that tight network of streets which cluster around the Place de Fourci, intent, apparently, on throwing his pursuers off the scent, for after a while he was running round and round in a circle.  Now up the Rue des Poules, then to the right and to the right again; back in the Place de Fourci.  Then straight across it once more to the Rue Contrescarpe, where he presently disappeared so completely from view that Tournefort thought that the earth must have swallowed him up.

Tournefort was a man capable of great physical exertion.  His calling often made heavy demands upon his powers of endurance; but never before had he grappled with so strenuous a task.  Puffing and panting, now running at top speed, anon brought to a halt by the doubling-up tactics of his quarry, his great difficulty was the fact that citizen Chauvelin did not wish the man Rateau to be apprehended; did not wish him to know that he was being pursued.  And Tournefort had need of all his wits to keep well under the shadow of any projecting wall or under cover of open doorways which were conveniently in the way, and all the while not to lose sight of that consumptive giant, who seemed to be playing some intricate game which well-nigh exhausted the strength of citizen Tournefort.

What he could not make out was what had happened to Chauvelin and to Gourdon.  They had been less than three hundred metres behind him when first this wild chase in and out of the Rue Contrescarpe had begun.  Now, when their presence was most needed, they seemed to have lost track both of him—­Tournefort—­and of the very elusive quarry.  To make matters more complicated, the shades of evening were drawing in very fast, and these narrow streets of the Faubourg were very sparsely lighted.

Just at this moment Tournefort had once more caught sight of Rateau, striding leisurely this time up the street.  The worthy agent quickly took refuge under a doorway and was mopping his streaming forehead, glad of this brief respite in the mad chase, when that awful churchyard cough suddenly sounded so close to him that he gave a great jump and well-nigh betrayed his presence then and there.  He had only just time to withdraw further still into the angle of the doorway, when Rateau passed by.

Tournefort peeped out of his hiding-place, and for the space of a dozen heart beats or so, remained there quite still, watching that broad back and those long limbs slowly moving through the gathering gloom.  The next instant he perceived Chauvelin standing at the end of the street.