As for the human element, Portiz was scarcely able to stand; Wagner had a fine case of the jitters and could do little more than botch things up royally if he tried to tackle a complicated task; Ward had gone to bed after a sixteen hour shift, and after two hours of sleep plus a dosage of unadulterated Venusian atmospherics had been awakened and called back to the station. The nervous tension was terrific. The three inarticulate men stood there while the seconds sped, Wagner staring around with desperation on his fat face, Silvy Ward clenching and unclenching his hands, Portiz leaning his drink-pliant body against the bank of keyers. Suddenly Ward broke the silence. "Wagner, get that trajectory keyer going. First check the interlock beam relay; the circuits seem to be okay, so it must be the relay. Portiz, get the portable glide beam transmitter unit and drive it out to the very base of the Hump on the eastern end of the field, and keep your receiver open on thirty-four megacycles; I'll give you directions from here. Come on, get going!" Wherewith Ward spun around to the Pali-Vanyi radio range transmitter. There was a peculiar smile on his face as he released the controls on the goniometer unit which governs the direction of the signals by reducing or increasing the radio frequency in the four range radiators. They'll be on the beam, he thought; these Martian boys won't take any chances of missing on the first stab for it would take them so long to maneuver around for a second attempt that the element of surprise would be lacking and their prey would have gotten away. They'll ride the beam in from the west. When they get directly over the range station they'll get the vertical radio signal from the station location marker and know that the field lies ten miles to the east and Pali-Vanyi ten miles south of the field. Switching their course ninety degrees they'll drop in right over the city and let go with everything they've got. They're probably on the beam now and four hundred miles to the west. They're due to hit the strato-winds which any astronaut knows will buck them around. The thunderheads will make their compass blotto so the only direction they can be sure of is due east on the beam. If we shift the beam slowly by rotating the goniometer counter-clockwise, the quadrants of the beam will be reversed. They'll swerve their course to follow, and gradually instead of getting the A signal to the south they'll be getting it from the east, and instead of an N from the north they'll have an N from the west. They'll come into Pali from the South-- * * * * *