His heart, I think.

He's got everything that ever ailed a man!" he said.
"Oh, George, you shouldn't have touched him," said Kate.
"Can't you see it will make me, if I can help him! Even Mother could see that," he cried.
"But if his heart is bad, the risk of massaging him is awful," said Kate as she hurried after George.
Kate looked at the man on the table, ran her hand over the heart region, and lifted terrified eyes to George.
"Do you think-- ?" he stammered.
"Sure of it!" she said, "but we can try.

Bring your camphor bottle, and some water," she cried to Mrs.Holt.
For a few minutes, they worked frantically.

Then Kate stepped back.
"I'm scared, and I don't care who knows it," she said.

"I'm going after Dr.James." "No, you are not!" cried George.