By this time the cab containing the lady had vanished, but the barrister made one despairing effort.
"For heaven's sake," he said to his captors, "take me where you will, but first follow that cab and ascertain its destination."
"What cab?" demanded one of his guards sarcastically.
"The cab which I wished our driver to overtake at the moment when you pounced on me."
"This is a mere trick," broke in the other. "Don't bother about his cab. We have got him safe enough, and let the commissaire deal with him now."
"Listen to me," cried Brett. "You are making a frightful mistake. Your action at this moment may cause irretrievable delay and loss. If you will only do as I tell you——"
"Shut up," growled the first man, "or it will be worse for you. Your best plan, my good fellow, is to keep a quiet tongue in your head."
It was not often that Brett lost his temper, but most certainly he lost it on this occasion. He was endowed with no small share of physical strength, and for an instant the wild notion came into his head that he might perhaps succeed in throwing the two detectives into the roadway and then overpower the driver, taking charge of the vehicle himself and trusting to luck to again catch sight of the vanished lady and her companion, who, he doubted not, had awaited her arrival at the quiet corner where she joined him.
Unconsciously he must have given some premonition of this desperate scheme, for the two policemen tightened their grasp, forced his hands higher up his back, and bent his head forward until he was in danger of having either his neck or his shoulder dislocated.