n, cheerfully noting down the name.

As they walked back toward Sixth Avenue he added, in a less sanguine
tone: "I'd undertake now to put the thing through if you could only put
me on the track of that cyanide."

Granice's heart sank. Yes--there was the weak spot; he had felt it from
the first! But he still hoped to convince McCarren that his case was
strong enough without it; and he urged the reporter to come back to his
rooms and sum up the facts with him again.

"Sorry, Mr. Granice, but I'm due at the office now. Besides, it'd be
no use till I get some fresh stuff to work on. Suppose I call you up
tomorrow or next day?"

He plunged into a trolley and left Granice gazing desolately after him.

Two days later he reappeared at the apartment, a shade less jaunty in
demeanor.

"Well, Mr. Granice, the stars in their courses are against you, as the
bard says. Can't get a trace of Flood, or of Leffler either. And you say
you bought the motor through Flood, and sold it through him, too?"

"Yes," said Granice wearily.

"Who bought it, do you know?"

Granice wrinkled his brows. "Why, Flood--yes, Flood himself. I sold it
back to him three months later."

"Flood? The devil! And I've ransacked the town for Flood. That kind of
business disappears as if the earth had swallowed it."

Granice, discouraged, kept silence.

"That brings us back to the poison," McCarren continued, his note-book
out. "Just go over that again, will you?"

And Granice went over it again. It had all been so simple at the
time--and he had been so clever in covering up his traces! As soon as he
decided on poison he looked about for an acquaintance who manufactured
chemicals; and there was Jim Dawes, a Harvard classmate, in the dyeing
business--just the man. But at the last moment it occurred to him that
suspicion might turn toward so obvious an opportunity, and he decided
on a more tortuous course. Another friend, Carrick Venn, a student of
medicine whom irremediable ill-health had kept from the practice of
his profession, amused his leisure with experiments in physics, for the
exercise of which he had set up a simple laboratory. Granice had the
habit of dropping in to smoke a cigar with him on Sunday afternoons, and
the friends generally sat in Venn's work-shop, at the back of the old
family house in Stuyvesant Square. Off this work-shop was the cupboard
of supplies, with its row of deadly bottles. Carrick Venn was an
original, a man of restles