“Well, do you feel better now?”

“Yes, thank you. I think I am getting normal again.”

He let me go. He lifted his eyes, looked upward, and I noticed his Adam’s apple for the first time; it resembles a broken spring, sticking out from beneath the upholstery of a divan.

Above us, not very high (about 50 meters) aeros were buzzing. By their low, slow flight and by the observation tubes which hung down, I recognized them. They were the aeros of the Guardians. But there were not two or three, as usual, there were about ten or twelve (I regret to have to confine myself to an approximate figure).

“Why are there so many today?” I dared to ask S- .

“Why? Hm.⁠ ⁠… A real physician begins to treat a patient when he is still well but on the way to becoming sick tomorrow, day-after-tomorrow or within a week. Prophylaxis! Yes!”