When Miss Comstock returned Jane could see that the chief stewardess was worried.

“Slim says the motor seems to be freezing up. It’s only a question of time before it will quit altogether.”

“Does that mean we’ll have to try for a landing?” asked Jane.

“He thinks he can keep going on the wing motors. He’s going to try but he said to be ready to jump if one of them stops.”

Standing in the aisle of the cold cabin, with the wind rocking the plane and the snow hiding the ground, Jane felt a chilling of her heart that was caused by something beside the sub-zero winter. The serum they carried was so desperately needed in the isolated town. Lives of children depended on the success of their trip. They must win through; the wing motors must continue their rhythmic beating.

Five minutes later the center motor quit firing altogether and the wing engines growled as the added burden came upon them. The wind seemed to have slackened slightly, but the mantle of snow still enfolded them in its fleecy whiteness.

The minutes crept on endlessly. They must be nearing the village if the pilot’s calculations were correct and the wind had not drifted them too far off their course.

Jane went to one of the windows and peered down. There was only the snow and the wind swirling it below them. Then they started down, feeling their way through the blizzard.

It was tricky work, a task that required the hand of a master pilot, for at any moment they might smash down out of the sky in a crash landing.

With nerves taut, the stewardesses watched the needle of the altimeter. The light flashed three times. It was the warning of trouble ahead.