"You've got it--hold it!" he exclaimed, waving his arms excitedly. "You see, Clio, their voices are pitched either higher or lower than ours--probably higher--and they've built an audio-frequency changer. He's nobody's fool, that lizard!" Nerado heard Costigan's voice, there was no doubt of that. His long neck looped and twisted in Nevian gratification; and although neither side could understand the other, both knew that intelligent speech and hearing were attributes common to the two races. This fact altered markedly the relations between captors and captives. The Nevians admitted among themselves that the strange bipeds might be quite intelligent, after all; and the Terrestrials at once became more hopeful. "It isn't so bad, if they can talk," Costigan summed up the situation. "We might as well take it easy and make the best of it, particularly since we haven't been able to figure out any possible way of getting away from them. They can talk and hear, and we can learn their language in time. Maybe we can make some kind of a deal with them to take us back to our own system, if we can't make a break." The Nevians being as eager as the Terrestrials to establish communication, Nerado kept the newly devised frequency changer in constant use. There is no need of describing at length the details of that interchange of languages. Suffice it to say that starting at the very bottom they learned as babies learn, but with the great advantage over babies of possessing fully developed and capable brains. And while the human beings were learning the tongue of Nevia, several of the amphibians (and incidentally Clio Marsden) were learning Triplanetarian; the two officers knowing well that it would be much easier for the Nevians to learn the logically-built common language of the Three Planets than to master the senseless intricacies of English. In a short time the two parties were able to understand each other after a fashion, by using a weird mixture of both languages. As soon as a few ideas had been exchanged, the Nevian scientists built transformers small enough to be worn collar-like by the Terrestrials, and the captives were allowed to roam at will throughout the great vessel; only the compartment in which was stored the dismembered pirate lifeboat being sealed to them. Thus it was that they were not left long in doubt when another fish-shaped cruiser of the void was revealed upon their lookout plates in the awful emptiness of interstellar space. "This is our sister-ship going to your Solarian system for a cargo of the iron which is so plentiful there," Nerado explained to his involuntary guests. "I hope the gang has got the bugs worked out of our super-ship!" Costigan muttered savagely to his companions as Nerado turned away. "If they have, that outfit will get something more than a load of iron when they get there!"