"Mrs. Moulton," he said firmly, "listen to me. What was the first question you asked me? 'Can I trust you?' And I told you you could.

This is no time for--for suicide." He shot the word out bluntly. "All may not be lost. I have sent for your husband. Muller is outside."

"Muller?" she cried. "He made the replica."

"Very well. I am going to clear this thing up. Come. You MUST."

It was all confused to me, the dash in a car to the little p.a.w.nbroker's on the first floor of a five-story tenement, the quick entry into the place by one of Muller's keys.

Over the safe in back was a framework like that which had covered Schloss' safe. Kennedy tore it away, regardless of the alarm which it must have sounded. In a moment he was down before it on his knees.

"This is how Schloss' safe was opened so quickly," he muttered, working feverishly. "Here is some of their own medicine."

He had placed the peculiar telephone-like transmitter close to the combination lock and was turning the combination rapidly.

Suddenly he rose, gave the bolts a twist, and the ponderous doors swung open.

"What is it?" I asked eagerly.

"A burglar's microphone," he answered, hastily looking over the contents of the safe. "The microphone is now used by burglars for picking combination locks. When you turn the lock, a slight sound is made when the proper number comes opposite the working point. It can be heard sometimes by a sensitive ear, although it is imperceptible to most persons. But by using a microphone it is an easy matter to hear the sounds which allow of opening the lock."

He had taken a yellow chamois bag out of the safe and opened it.

Inside sparkled the famous Moulton diamonds. He held them up--in all their wicked brilliancy. No one spoke.

Then he took another yellow bag, more dirty and worn than the first. As he opened it, Mrs. Moulton could restrain herself no longer.

"The replica!" she cried. "The replica!"

Without a word, Craig handed the real necklace to her. Then he slipped the paste jewels into the newer of the bags and restored both it and the empty one to their places, banged shut the door of the safe, and replaced the wooden screen.

"Quick!" he said to her, "you have still a minute to get away.

Hurry--anywhere--away--only away!"

The look of grat.i.tude that came over her face, as she understood the full meaning of it was such as I had never seen before.

"Quick!" he repeated.

It was too late.

"For G.o.d's sake, Kennedy," shouted a voice at the street door, "what are you doing here?"

It was McLear himself. He had come with the Hale patrol, on his mettle now to take care of the epidemic of robberies.

Before Craig could reply a cab drew up with a rush at the curb and two men, half fighting, half cursing, catapulted themselves into the shop.

They were Winters and Moulton.

Without a word, taking advantage of the first shock of surprise, Kennedy had clapped a piece of chemical paper on the foreheads of Mrs.

Moulton, then of Moulton, and on Muller's. Oblivious to the rest of us, he studied the impressions in the full light of the counter.

Moulton was facing his wife with a scornful curl of the lip.

"I've been told of the paste replica--and I wrote Schloss that I'd shoot him down like the dog he is, you--you traitress," he hissed.

She drew herself up scornfully.

"And I have been told why you married me--to show off your wicked jewels and help you in your--"

"You lie!" he cried fiercely. "Muller--some one--open this safe--whosever it is. If what I have been told is true, there is in it one new bag containing the necklace. It was stolen from Schloss to whom you sold my jewels. The other old bag, stolen from me, contains the paste replica you had made to deceive me."

It was all so confused that I do not know how it happened. I think it was Muller who opened the safe.

"There is the new yellow bag," cried Moulton, "from Schloss' own safe.

Open it."

McLear had taken it. He did so. There sparkled not the real gems, but the replica.

"The devil!" Moulton exclaimed, breaking from Winters and seizing the old bag.

He tore it open and--it was empty.

"One moment," interrupted Kennedy, looking up quietly from the counter.

"Seal that safe again, McLear. In it are the Schloss jewels and the products of half a dozen other robberies which the dupe Muller--or Stein, as you please--pulled off, some as a blind to conceal the real criminal. You may have shown him how to leave no finger prints, but you yourself have left what is just as good--your own forehead print.

McLear--you were right. There's your criminal--Lynn Moulton, professional fence, the brains of the thing."

CHAPTER XIX

THE GERM LETTER

Lynn Moulton made no fight and Kennedy did not pursue the case, for, with the rescue of Antoinette Moulton, his interest ceased.

Blackmail takes various forms, and the Moulton affair was only one phase of it. It was not long before we had to meet a much stranger attempt.

"Read the letter, Professor Kennedy. Then I will tell you the sequel."

Mrs. Hunter Blake lay back in the cushions of her invalid chair in the sun parlor of the great Blake mansion on Riverside Drive, facing the Hudson with its continuous reel of maritime life framed against the green-hilled background of the Jersey sh.o.r.e.

Her nurse, Miss Dora Sears, gently smoothed out the pillows and adjusted them so that the invalid could more easily watch us. Mrs.

Blake, wealthy, known as a philanthropist, was not an old woman, but had been for years a great sufferer from rheumatism.

I watched Miss Sears eagerly. Full-bosomed, fine of face and figure, she was something more than a nurse; she was a companion. She had bright, sparkling black eyes and an expression about her well-cut mouth which made one want to laugh with her. It seemed to say that the world was a huge joke and she invited you to enjoy the joke with her.

Kennedy took the letter which Miss Sears proffered him, and as he did so I could not help noticing her full, plump forearm on which gleamed a handsome plain gold bracelet. He spread the letter out on a dainty wicker table in such a way that we both could see it.

We had been summoned over the telephone to the Blake mansion by Reginald Blake, Mrs. Blake's eldest son. Reginald had been very reticent over the reason, but had seemed very anxious and insistent that Kennedy should come immediately.