I am glad, too, although there are many difficulties. But,
furthermore, he enjoined me to--"

"Keep an eye on Antony! Yes, yes--but, heavens! he didn't know him for
what he is!"

Dr. Cairn turned to him again.

"He did not; by a divine mercy, he never knew--what we know. But"--his
clear eyes were raised to his son's--"the charge is none the less
sacred, boy!"

The younger man stared perplexedly.

"But he is nothing less than a ----"

His father's upraised hand checked the word on his tongue.

"_I_ know what he is, Rob, even better than you do. But cannot you see
how this ties my hands, seals my lips?"

Robert Cairn was silent, stupefied.

"Give me time to see my way clearly, Rob. At the moment I cannot
reconcile my duty and my conscience; I confess it. But give me time.
If only as a move--as a matter of policy--keep in touch with Ferrara.
You loathe him, I know; but we _must_ watch him! There are other
interests--"

"Myra!" Robert Cairn flushed hotly. "Yes, I see. I understand. By
heavens, it's a hard part to play, but--"

"Be advised by me, Rob. Meet stealth with stealth. My boy, we have
seen strange ends come to those who stood in the path of someone. If
you had studied the subjects that I have studied you would know that
retribution, though slow, is inevitable. But be on your guard. I am
taking precautions. We have an enemy; I do not pretend to deny it; and
he fights with strange weapons. Perhaps I know something of those
weapons, too, and I am adopting--certain measures. But one defence,
and the one for you, is guile--stealth!"

Robert Cairn spoke abruptly.

"He is installed in palatial chambers in Piccadilly."

"Have you been there?"

"No."

"Call upon him. Take the first opportunity to do so. Had it not been
for your knowledge of certain things which happened in a top set at
Oxford we might be groping in the dark now! You never liked Antony
Ferrara--no men do; but you used to call upon him in college. Continue
to call upon him, in town."

Robert Cairn stood up, and lighted a cigarette.

"Right you are, sir!" he said. "I'm glad I'm not alone in this thing!
By the way, about--?"

"Myra? For the present she remains at the house. There is Mrs. Hume,
and all the old servants. We shall see what is to be done, later. You
might run over and give her a look-up, though."

"I will, sir! Good-bye."

"Good-bye," said Dr. Cairn, and pressed the bell which summoned
Marston to usher out the caller, a