abruptly
upon the ambulance, screened by the clump of naked elms at the side of
the road.

"You get in first, Doctor," ordered Blaine, significantly. "You've got
to look after your patient now."

As the Doctor obeyed, Mac Alarney, with a shrewd gleam in his eyes,
turned to the detective.

"I think I'd better ride with him, too, Mr. Blaine," he observed. "You
don't know who you can trust these days. Your ambulance driver may
give you the slip."

"All right, Mac!" Blaine assented, with bluff heartiness. "We'll both
ride with him! Did you think I'd try to double-cross you, too? I can't
blame you, after the rotten deal that's been handed to you, but we
won't waste time arguing. Here's the stretcher. Come on, shove him
in!"

The Doctor had been wondering when the denouement of this adventure
would be. Now it came without warning, with a startling suddenness
which left him dazed and agape.

The inert body of his patient was laid carefully beside him, and he
glanced out of the ambulance door in time to see Mac Alarney dismiss
his burly assistant, and turn to enter the vehicle. His foot was
already upon the lowest step, when the Doctor saw Blaine raise his
hand to his lips. A short, sharp blast of a whistle pierced the air,
and in an instant a dozen men had sprung out of the darkness and
leaped upon the two surprised miscreants. Then ensued a struggle,
brief but awful to the onlooker in its silent, grim ferocity, as the
two separate knots of men battled each about their central orbit. The
scuffle of many feet on the hard-packed road, the mutter of curses,
the dull thud of blows, the hoarse, strangulated breathing of men
fighting against odds to the last ounce of their strength, came to the
Doctor's startled ears in a confused babel of half-suppressed sound,
with the purring drone of the two engines as an undertone.

A minute, and it was all over. The thick-set Al went down like a
felled ox, and Mac Alarney wavered under an avalanche of blows and
crumpled to his knees. Handcuffed and securely bound, the two were
bundled into Blaine's waiting car.

"Paddington never double-crossed me!" groaned Mac Alarney, before the
door closed upon him. "But you did, Blaine! Just as I meant to get
him, I'll get you! I fell for your d--d scheme, and since you've got
the goods on me, I suppose I'll go up, but God help you when I come
out! I can wait--it'll be the better when it comes!"

"But the others--" queried the Doctor, as he a