-it was
Bridgers, the man he had left strapped and bound in the
"ambulance-room," and Beale cursed the folly which had induced him to
leave the revolver behind.

"I'll fix you--you brute!" screamed Bridgers, "get away from him--ah!"

Beale's hand flew up, a pencil of flame quivered and again the vault
trembled to the deafening report.

But Bridgers had dropped to cover. Again he shot, this time with
unexpected effect. The bullet struck the fuse-box on the opposite wall
and all the lights went out.

Beale was still holding the glass tube, and this Milsom had seen. Quick
as thought he hurled himself upon the detective, his big, powerful hands
gripped the other's wrist and wrenched it round.

Beale set his teeth and manoeuvred for a lock grip, but he was badly
placed, pressed as he was against the edge of the bench. He felt van
Heerden's fingers clawing at his hand and the tube was torn away.

Then somebody pulled the revolver from the other hand and there was a
scamper of feet. He groped his way through the blackness and ran into
the pile of boxes. A bullet whizzed past him from the half-crazy
Bridgers, but that was a risk he had to take. He heard the squeak of an
opening door and stumbled blindly in its direction. Presently he found
it. He had watched the other men go out and discovered the steps--two
minutes later he was in the street.

There was no sign of either of the two men. He found a policeman after
he had walked half a mile, but that intelligent officer could not leave
his beat and advised him to go to the police station. It was an
excellent suggestion, for although the sergeant on duty was wholly
unresponsive there was a telephone, and at the end of the telephone in
his little Haymarket flat, a Superintendent McNorton, the mention of
whose very name galvanized the police office to activity.

"I have found the factory I've been looking for, McNorton," said Beale.
"I'll explain the whole thing to you in the morning. What I want now is
a search made of the premises."

"We can't do that without a magistrate's warrant," said McNorton's
voice, "but what we can do is to guard the premises until the warrant is
obtained. Ask the station sergeant to speak on the 'phone--by the way,
how is Miss Cresswell, better, I hope?"

"Much better," said the young man shortly.

It was unbelievable that she could ever fill his heart with the ache
which came at the mention of her name.

He made way for the station sergea