The Doctor drew himself up with simple dignity, quite free from bombast or arrogance.

“I am not afraid,” he replied, quietly. “I am armed, and am fully prepared to help protect my patient.”

“Armed?” the detective asked, sharply.

For answer, Doctor Alwyn drew from his capacious coat pocket a huge, old-fashioned pistol, and held it out to Blaine. The latter took it from him without ceremony.

“A grave mistake, Doctor. I am glad you told me, in time. Fire-arms are unnecessary for your own protection, and would be a positive menace to our plans for getting your patient safely away. Gun-play is the last thing we must think of; my men will attend to all that, if it comes to a show-down.”

The Doctor watched him in silence as he slipped the pistol under one of the side seats. If his confidence in the great man beside him faltered for the moment, he gave no sign, but turned his attention again to the window. They were now rapidly traversing the suburbs, where the houses were widely separated by stretches of vacant lots, and the streets deserted and but dimly lighted. Soon they rattled over a narrow railroad bridge, and Doctor Alwyn exclaimed:

“By George! This is the way we went last night! 242 With all my careful thought, I forgot about that bridge until this moment!”

Minutes passed, long minutes which seemed like hours to the overstrained nerves of the Doctor, while they speeded through the open country.

All at once, from just behind them came a hideous, wailing cry, which swelled in volume to a screech and ended abruptly.

Doctor Alwyn grasped Blaine’s arm.