"But, my machine ?" "I will attend to your machine." "I should hate to leave it there on the roof." "It will not be left on the roof." "I don't understand, exactly--" "There will be very many things you do not understand before this expedition is over and done with.

I need say no more." Sharply he clapped his hands, thrice.

In a moment, Rrisa appeared at the door.

The Master spoke a few guttural, aspirated words of Arabic.
Rrisa beckoned the stranger, who obeyed.
At the exit he faced about and sharply saluted.

The Master returned it.