from you, and she's very much alone."

"Is she?"

"Are you stopping on much longer in London?"

"Till the twelfth or fifteenth of August."

"She is stopping on, too."

"Mrs. Chepstow! In the dog-days!"

"She doesn't seem to have anywhere special to go to."

"Oh!"

Isaacson opened a book, and laid his hand upon a page. It happened to be
a book on poisons and their treatment. He smoothed the page down
mechanically and kept his hand there.

"I say, Isaacson, you couldn't have the blood-lust?"

"I hope not. I think not."

"I believe you hate it as I do, hate and loathe it with all your soul.
But I've always felt that you think for yourself, and don't care a rap
what the world is thinking. I've looked in to-night to say good-bye, and
to ask you, if you can get the time, just to give an eye to--to Mrs.
Chepstow now and again. I know she would value a visit from you, and she
really is infernally lonely. If you go, she won't bore you. She's a
clever woman, and cares for things you care for. Will you look in on her
now and then?"

Isaacson lifted his hand from the book.

"I will call upon her," he said.

"Good!"

"But are you sure she wishes it?"

"Quite sure--for she told me so."

The simplicity of this answer made Isaacson's mind smile and something
else in him sigh.

"I have to go into the country," Nigel said. "I've got to see Harwich
and Zoe, my sister-in-law you know, and my married sister--"

A sudden look of distress came into his eyes. He got up. The look of
distress persisted.

"Good-night, Isaacson, old fellow!"

He grasped the Doctor's hand firmly, and his hand was warm and strong.

"Good-night. I like to feel I know one man who thinks so entirely for
himself as you do. For--I know you do. Good-bye."

The look of distress had vanished, and his sincere eyes seemed to shine
again with courage and with strength.

"Good-bye."

When he was gone, Isaacson stood by the mantel-piece for nearly five
minutes, thinking and motionless. The sound of the little clock striking
roused him. He lifted his head, looked around him, and was just going to
switch off the light, when he noticed the open book on his table. He
went to shut it up.

"It must be ever remembered that digitalin is a cumulative poison, and
that the same dose, harmless if taken once, yet frequently repeated
becomes deadly; this peculiarity is shared by all poisons affecting the
heart."

He stood looking at the page.

"This pe