Lalla Dee, the Venusian girl, had silently entered the cabin door behind him and was covering both him and the Martian with a beam-pistol.
Her face was no longer that of a soft, pretty schoolgirl but was chiseled in lines of stern resolve.
"Lalla Dee!" cried Crane. "What does this mean?"
"It means, Rab Crane," she said steadily, "that just as you work for Earth, and Kark Al for Mars, I work for Venus! Yes, I'm a member of the Venusian Secret Service. Headquarters sent me on this ship at the last minute when they learned that Doctor Alph's brain had been stolen. We had been trying to get Doctor Alph's secret for ourselves, of course, and knew that the thief would try to get away on the first ship.
"I thought at first that you had the brain, but I soon saw that you didn't, that you were on the trail of it just as Kin Nilga and myself were. So I watched you, thinking you might know enough to lead me to the person who did have it. And you've done so. When you asked about the cabins tonight, I kept watch outside them."
She held out her hand to the smiling little Martian.
"The vial of culture, Kark Al," she said. "It and, that brain go back to Venus."
"Lalla Dee, you'll have to kill me before I'll let you get the culture and the brain, to be used, perhaps, against Earth!" Rab Crane cried.
"I'm sorry, Crane, really," she said. "But just as you love Earth, so do I love Venus."
"You two need not continue the useless argument," Kark Al said. "The culture and the brain go where it has always been destined that they should — to Mars."