y,
through no effort of his, was thrust into his hand--No. 15,836!

Jimmie Dale, the gently ironic smile still on his lips, those slim,
supersensitive fingers of his subconsciously noting that the texture of
the envelope was the same as she always used, retraced his steps to the
sidewalk.

"Number fifteen thousand eight hundred and thirty-six," said Jimmie Dale
aloud--and halted at the curb as though rooted to the spot. It sounded
strangely familiar, that number! He repeated it over again slowly:
"One-five-eight-three-six." And the smile left his lips, and upon his
face came the look of a chastened child. She had used a duplicate plate!
Fifteen thousand eight hundred and thirty-six was the number of one of
his own cars--his own particular runabout!

For a moment longer he stood there, undecided whether to laugh or swear,
and then his eyes fastened mechanically on the envelope he was twirling
in his fingers. Here, at least, was something that was not elusive;
that, on the contrary, as a hundred others in the past had done,
outlined probably a grim night's work ahead for the Gray Seal! And, if
it were as those others had been, every minute from the moment of its
receipt was precious time. He stepped under the nearest street light,
and tore the envelope open.

"Dear Philanthropic Crook," it began--and then followed two closely
written pages. Jimmie Dale read them, his lips growing gradually
tighter, a smouldering light creeping into his dark eyes, and once he
emitted a short, low whistle of consternation--that was at the end, as
he read the post-script that was heavily underscored: "Work quickly.
They will raid to-night. Be careful. Look out for Kline, he is the
sharpest man in the United States secret service."

For a brief instant longer, Jimmie Dale stood under the street lamp,
his mind in a lightning-quick way cataloguing every point in her letter,
viewing every point from a myriad angles, constructing, devising,
mapping out a plan to dove-tail into them--and then Jimmie Dale swung on
a downtown bus. There was neither time nor occasion to go home now--that
marvellous little kit of burglar's tools that peeped from their tiny
pockets in that curious leather undervest, and that reposed now in
the safe in his den, would be useless to him to-night; besides, in the
breast pocket of his coat, neatly folded, was a black silk mask, and,
relics of his role of Larry the Bat, an automatic revolver, an
electric flashlight, a