Secret of the Earth Star by Henry Kuttner

"So," said the fat little man with the shaved head, "so you want to join the Legion. Eh?"

Tony looked him over. The dingy office in the outskirts of the North African city was unimpressive. But, somehow, the little man was not. He wore dirty white tropical linens, his face glistened with sweat, but to the three brothers he represented fate. On his decision their destiny would depend.