But they only waved at us, skimming down the length of the corridor, seeming to avoid a smash a dozen times by the smallest margin of chance, stopping miraculously at the further end, hanging poised in mid-air, wheeling, coming back, undulating up and down.

Grantline clung to me. "By the gods of the airways!"

In spite of my astonished horror I could not but share Grantline's obvious admiration. Three of four other men were watching. The girls were amazingly skillful, no doubt of that. There was not a man among us who could have handled that gravity-platform indoors, not one who would have had the brash temerity to try it.

The platform landed with the grace of a humming bird at our feet, the girls dexterously balancing so that it came to rest swiftly, without the least bump.

I confronted them. "Anita, what are you doing?"

She stood up, flushed and smiling.

"Practising."

Imperturbable girls! The product of their age. Oblivious to the brigand attack, they were in here practising!

"What for?" I demanded.

Venza's roguish eyes twinkled at me. Her hands went to her slim hips with a gesture of defiance.