Nothing more could be got out of him until the cab swept round the corner by the Hotel Saint Louis, where they got out, and he led the party up a side lane already in deep shadow with the growing dusk. Once, when the Duke impatiently asked whether Hirsch was guilty of treason or not, he answered rather absently:
"No; only of ambition--like Caesar." Then he somewhat inconsequently added:
"He lives a very lonely life; he has had to do everything for himself."
"Well, if he's ambitious, he ought to be satisfied now," said Flambeau rather bitterly. "All Paris will cheer him now our cursed Colonel has turned tail."
"Don't talk so loud," said Father Brown, lowering his voice, "your cursed Colonel is just in front."
The other two started and shrank farther back into the shadow of the wall, for the sturdy figure of their runaway principal could indeed be seen shuffling along in the twilight in front, a bag in each hand. He looked much the same as when they first saw him, except that he had changed his picturesque mountaineering knickers for a conventional pair of trousers. It was clear he was already escaping from the hotel.
The lane down which they followed him was one of those that seem to be at the back of things, and look like the wrong side of the stage scenery. A colourless, continuous wall ran down one flank of it, interrupted at intervals by dull-hued and dirt-stained doors, all shut fast and featureless save for the chalk scribbles of some passing gamin. The tops of trees, mostly rather depressing evergreens, showed at intervals over the top of the wall, and beyond them in the grey and purple gloaming could be seen the back of some long terrace of tall Parisian houses, really comparatively close, but somehow looking as inaccessible as a range of marble mountains. On the other side of the lane ran the high gilt railings of a gloomy park.
Flambeau was looking round him in rather a weird way.
"Do you know," he said, "there is something about this place that--"
"Hullo!" called out the Duke sharply; "that fellow's disappeared.
Vanished, like a blasted fairy!"
"He has a key," explained their clerical friend. "He's only gone into one of these garden doors," and as he spoke they heard one of the dull wooden doors close again with a click in front of them.
Flambeau strode up to the door thus shut almost in his face, and stood in front of it for a moment, biting his black moustache in a fury of curiosity. Then he threw up his long arms and swung himself aloft like a monkey and stood on the top of the wall, his enormous figure dark against the purple sky, like the dark tree-tops.
The Duke looked at the priest. "Dubosc's escape is more elaborate than we thought," he said; "but I suppose he is escaping from France."
"He is escaping from everywhere," answered Father Brown.
Valognes's eyes brightened, but his voice sank. "Do you mean suicide?" he asked.
"You will not find his body," replied the other.
A kind of cry came from Flambeau on the wall above.
"My God," he exclaimed in French, "I know what this place is now!
Why, it's the back of the street where old Hirsch lives. I thought I could recognize the back of a house as well as the back of a man."
"And Dubosc's gone in there!" cried the Duke, smiting his hip.
"Why, they'll meet after all!" And with sudden Gallic vivacity he hopped up on the wall beside Flambeau and sat there positively kicking his legs with excitement. The priest alone remained below, leaning against the wall, with his back to the whole theatre of events, and looking wistfully across to the park palings and the twinkling, twilit trees.
