I was utterly amazed, but at the same time convinced.

I had not seen the dog since my arrival in Paris, and it was impossible for him to have known where to find my handkerchief, or to recognize it as being mine, unless through the means Heliobas had explained.
"Can you command human beings so ?" I asked, with a slight tremor of nervousness.
"Not all," returned Heliobas quietly.

"In fact, I may say, very few.
Those who are on my own circle of power I can, naturally, draw to or repel from me; but those who are not, have to be treated by different means.

Sometimes cases occur in which persons, at first NOT on my circle, are irresistibly attracted to it by a force not mine.
Sometimes, in order to perform a cure, I establish a communication between myself and a totally alien sphere of thought; and to do this is a long and laborious effort.

But it can be done." "Then, if it can be done," said Prince Ivan, "why do you not accomplish it for me ?" "Because you are being forcibly drawn towards me without any effort on my part," replied Heliobas, with one of his steady, keen looks.