ease,
Sir Henry.) I have the honour to make you acquainted with Sir Henry
Wilding, Cleek; he needs you, my dear fellow."

"Delighted--in both instances. My compliments, Sir Henry. By any chance
that Sir Henry Wilding whose mare, Black Riot, is the favourite for next
Wednesday's Derby?"

"Yes--that very man, Mr. Cleek; and if--"

"Don't get excited and don't turn, please; our friend the policeman is
looking this way. What's the case? One of 'nobbling'? Somebody trying to
get at the mare?"

"Yes. A desperate 'somebody,' who doesn't stop even at murder. A very
devil incarnate who seems to possess the power of invisibility, and who
strikes in the dark. Save me, Mr. Cleek! All I've got in the world is at
stake, and if anything happens to Black Riot, I'm a ruined man."

"Yar-r-r!" yawned the elderly sea captain, rising and stretching. "I do
believe, constable, I've been asleep. Warm weather, this, for May. A
glorious week for Epsom. Shan't see you to-morrow, I'm afraid. Perhaps
shan't see you until Thursday. Here, take that, my lad, and have
half-a-crown's worth on Black Riot for the Derby; she'll win it, sure."

"Thanky, sir. Good luck to you, sir."

"Same to you, my lad. Good day." Then the old gentleman in the top hat
and white spats moved slowly away, passed down the tree-shaded walk,
passed the romping children, passed the Princess Louise's statue of
Queen Victoria, and, after a moment, vanished. Ten minutes later, when
Narkom and Sir Henry returned to the waiting motor, they found him
seated within it awaiting them, as he had promised. Giving Lennard
orders to drive about slowly in the least frequented quarters, while
they talked, the superintendent got in with Sir Henry, and opened fire
on the "case" without further delay.

"My dear Cleek," he said, "as you appear to know all about Sir Henry and
his famous mare, there's no need to go into that part of the subject, so
I may as well begin by telling you at once that Sir Henry has come up to
town for the express purpose of getting you to go down to his place in
Suffolk to-night in company with him, as his only hope of outwitting a
diabolical agency which has set out to get at the horse and put it out
of commission before Derby Day, and in the most mysterious, the most
inscrutable manner ever heard of, my dear chap. Already one groom who
sat up to watch with her has been killed, another hopelessly paralysed,
and to-night Logan, the mare's trainer, is to sit up wit