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! 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.

"The motor-horn!" he gasped. "The car I was in last night!"

The detective nodded shortly, without speaking, and leaning forward,
stared fixedly out of the window. A long, low-bodied limousine
appeared, creeping slowly up, inch by inch, until it was fairly
abreast of them. The curtain at the window was lowered, and the
chauffeur sat immovable, with his face turned from them, as the two
cars whirled side by side along the hard, glistening road. Blaine
leaned forward, and pressed the electric bell rapidly twice, and there
began a curious game. The other car put on extra speed and darted
ahead--their own shot forward and kept abreast of it. It slowed
suddenly, and made as if to swerve in behind; Blaine's driver slowed
also, until both cars almost came to a grinding halt. Three times
these maneuvers were repeated, and then there occurred what the
detective had evidently anticipated.

The curtain in the other car shot up; the window descended with a bang
and a huge, burly figure leaned half-way out. Henry Blaine noiselessly
lowered their own window, and suddenly flashed an electric pocket
light full in the heavy-jowled face, empurpled with inarticulate
rage.

"Is that your man?" he asked, quickly.

"The one with the three fingers! Yes! That's the man!" whispered the
Doctor, hoarsely.

"That's Mac Alarney." Blaine pressed the electric bell again, and
their own car lunged forward in a spurt of speed which left the other
hopelessly behind, although it was manifestly making desperate efforts
to overtake and pass them.

"Do you suppose he suspected our errand?" the Doctor asked.

"Suspected? Lord bless you, man, he knows! He had already passed the
two open cars full of my men, and the ambulance. He'd give ten years
of his life to beat us out and reach his place ahead of us to-night,
but he hasn't a chance in the world unless we b