Encouraged by this intelligent comprehension, Derek went on to define the good offices he would expect from Diane.  She should come to his house not only as Dorothea’s inseparable companion, but as a sort of warder-in-chief, armed, by his authority, with all the powers of command.  There was no use in doing things by halves; and if Dorothea needed discipline she had better get it thoroughly, and be done with it.  It was not a thing which he, Derek, would want to see last forever; but while it did last it ought to be effective, and he would look to Diane to make it so.  As it was not becoming that a daughter of his should need a bodyguard of youths, Diane would undertake the task of breaking up Dorothea’s circle.  Young men might still be permitted “to call,” but under Diane’s supervision, while Dorothea sat in the background, as a maiden should.  Diane would make it a point to know the lads personally, so as to discriminate between them, and exclude those who for one reason or another might not be desirable friends.  As for Mr. Carli Wappinger, the door was to be rigorously shut against him.  Here the question was not one of gradual elimination, but of abrupt termination to the acquaintanceship.  He must request Diane to see to it that, as far as possible, Dorothea neither met the young man, nor held communication with him, on any pretext whatever.  He laid down no rule in the case of Mrs. Wappinger, but it would follow as a natural consequence that the mother should be dropped with the son.  These might seem drastic measures to Dorothea, to begin with; but she was an eminently reasonable child, and would soon come to recognize their wisdom.  After all, they were only the conditions to which, as he had been given to understand, other young girls were subjected, so that she would have nothing to complain of in her lot.  The probability of his own departure for South America, with an absence lasting till the spring, would make it necessary for Diane to use to the full the powers with which he commissioned her.  He trusted that he made himself clear.

For some minutes after he ceased speaking Diane sat looking meditatively at the fire.  When she spoke her voice was low, but the ring of decision in it was not to be mistaken.

“I’m afraid I couldn’t accept the position, Mr. Pruyn.”

Derek’s start of astonishment was that of a man who sees intentions he meant to be benevolent thrown back in his face.

“You couldn’t—?  But surely—?”

“I mean, I couldn’t do that kind of work.”

“But I thought you were looking for it—­or something of the sort.”

“Yes; something of the sort, but not precisely that.”

“And it’s precisely that that I wish to have done,” he said, in a tone that betrayed some irritation; “so I suppose there is no more to be said.”

“No; I suppose not.  In any case,” she added, rising, “I must thank you for being so good as to think of me; and if I feel obliged to decline your proposition, I must ask you to believe that my motives are not petty ones.  Now I will say good-afternoon.”