But Ouaouaoua brusquely made a right-about face and headed toward the Boulevard des Batignolles.
"Are we going to keep this up much longer?" inquired Wulf, who by this time was breathless and weary.
"You can go if you like," growled Juve without turning his head. In his intense absorption, Juve failed to notice the menacing and ironical look the officer directed at him.
Ouaouaoua now turned down the Rue Notre-Dame-de-Lorette hastening his speed. The two men had some difficulty in keeping up with him. Suddenly he disappeared at the corner of the Rue Saint Lazare and the Rue Lamartine. Juve sprang forward just in time to see the white draped figure vanish down the stairs leading to the underground Station of the Nord-Sud.
The Station was lighted and the ticket windows open. The morning's traffic had begun.
"Have you just seen a queerly dressed man?" he asked one of the porters.
"He has just bought his ticket, Monsieur."
Juve flung down a coin, seized two coupons and without waiting for the change hurried onto the platform. The first morning train was waiting, due to start in five minutes. A quick search through the carriages disclosed the object of Juve's search. He was standing in the first carriage by the door of the driver's compartment. While Juve eyed him eagerly, the Primitive Man in turn was watching the detective.
The conductors and employés were standing gossiping by the ticket office, and the station was almost deserted at this early morning hour.
Juve remained on the platform with Wulf. As a preliminary to making his arrest, he took out his revolver, and held it in the palm of his hand. Suddenly he gave a yell and sprang forward. Ouaouaoua, taking advantage of the engine driver's absence, had entered his compartment and pulled the levers.