then?"

"Well, I found my plans very seriously menaced. It looked as if the pair
might take an immediate departure, and so necessitate very prompt and
energetic measures on my part. At the church door, however, they
separated, he driving back to the Temple, and she to her own house. 'I
shall drive out in the park at five as usual,' she said, as she left him.
I heard no more. They drove away in different directions, and I went off
to make my own arrangements."

"Which are?"

"Some cold beef and a glass of beer," he answered, ringing the bell. "I
have been too busy to think of food, and I am likely to be busier still
this evening. By the way, doctor, I shall want your cooperation."

"I shall be delighted."

"You don't mind breaking the law?"

"Not in the least."

"Nor running a chance of arrest?"

"Not in a good cause."

"Oh, the cause is excellent!"

"Then I am your man."

"I was sure that I might rely on you."

"But what is it you wish?"

"When Mrs. Turner has brought in the tray I will make it clear to you.
Now," he said, as he turned hungrily on the simple fare that our landlady
had provided, "I must discuss it while I eat, for I have not much time. It
is nearly five now. In two hours we must be on the scene of action. Miss
Irene, or Madame, rather, returns from her drive at seven. We must be at
Briony Lodge to meet her."

"And what then?"

"You must leave that to me. I have already arranged what is to occur.
There is only one point on which I must insist. You must not interfere,
come what may. You understand?"

"I am to be neutral?"

"To do nothing whatever. There will probably be some small unpleasantness.
Do not join in it. It will end in my being conveyed into the house. Four
or five minutes afterwards the sitting-room window will open. You are to
station yourself close to that open window."

"Yes."

"You are to watch me, for I will be visible to you."

"Yes."

"And when I raise my hand--so--you will throw into the room what I give
you to throw, and will, at the same time, raise the cry of fire. You quite
follow me?"

"Entirely."

"It is nothing very formidable," he said, taking a long, cigar-shaped roll
from his pocket. "It is an ordinary plumber's smoke-rocket, fitted with a
cap at either end, to make it self-lighting. Your task is confined to
that. When you raise your cry of fire, it will be taken up by quite a
number of people. You may then walk to the end of the street, and I