There was some reason why Ercole, who had heard, did not get down and tell the Professor, who had noticed nothing.  One reason, and a good enough one, was that whoever it was that had opened the door so cautiously, it certainly was not the man they were all hunting that night.  Yet since Ercole knew the little house, and probably knew who lived there, and that it belonged to Marcello, it might have been supposed that he would have told the latter, whose footsteps were heard on the gravel a few moments afterwards.  But though Marcello stood a moment by the wheel close to Ercole, and spoke across him to the cabman, Ercole said nothing.  Nino had not growled at Marcello, even before the latter had appeared, for Nino had a good memory, for a dog, and doubtless remembered long days spent by the Roman shore, and copious leavings thrown to him from luxurious luncheons.  Before they had left the villa he had sniffed at Marcello’s clothes and hands in a manner that was meant to be uncommonly friendly, though it might not have seemed reassuring to a stranger; and Marcello had patted his huge head, and called him by name.

The young man had given the cabman the address of the office of the Chief of Police, and when he had got in and hooked up the leathern apron, the cab rolled away over the stones through the dark streets, towards the bridge of Saint Bartholomew.

Within the house Regina sat alone, as Marcello had found her, her chin resting on the back of her closed hand, her elbow on her knee, her eyes gazing at the bright little fire that blazed on the polished hearth.  Her hair was knotted for the night, low down on her neck, and the loose dressing-gown of dove-coloured silk plush was unfastened at the neck, where a little lace fell about her strong white throat.

She had sprung to her feet in happy surprise when Marcello had entered the room, though it was not two hours since he had left her, and she could still smell the smoke of his last cigarette.  She had felt a sudden chill when she had seen his face, for she never saw him look grave and preoccupied without believing that he had grown suddenly tired of her, and that the end had come.  But then she had seen his eyes lighten for her, and she had known that he was not tired of her, but only very much in earnest and very much in a hurry.

He had bidden her find out from Settimia where Corbario was, if the woman knew it; he had told her to find out at any cost, and had put a great deal of emphasis on the last words.  In answer to the one question she asked, he told her that Corbario was a murderer, and was trying to escape.  He had not time to explain more fully, but he knew that he could count on her.  She did not love Folco Corbario, and she came of a race that could hate, for it was the race of the Roman hill peasants.  So he left her quickly and went on.