For five minutes or so in petrified silence the higher being observed the lower one, peering hard at the out-of-focus specimen. There was complete silence all around. Pankrat had gone to sleep in his cubby-hole in thes vestibule, and only once there came a far-off gentle and musical tinkling of glass in cupboards-that was Ivanov going out and locking his laboratory. The entrance door groaned behind him. Then came the Professor's voice. To whom his question was addressed no one knows. What on earth is that? I don't understand..." A late lorry rumbled down Herzen Street, making the old walls of the Institute shake. The shallow glass bowl with pipettes tinkled on the table. The Professor turned pale and put his hands over the microscope, like a mother whose child is threatened by danger. There could now be no question of Persikov turning the knob.