"Two is all that can work here at once, but you should know how to take hold in case one of us goes out. And while you're changing suits you'd better put on some stuff I've got here--Service special phones and detectors. Stick this little disk onto your chest with this bit of tape; low down, out of sight. Just under your wishbone is the best place. Take off your wrist-watch and wear this one _continuously_--never take it off for a second. Put on these pearls, and wear them all the time, too. Take this capsule and hide it against your skin, some place where it can't be found except by the most rigid search. Swallow it in an emergency--it goes down easily and works just as well inside as outside. It is the most important thing of all--you can get along with it alone if you lose everything else, but without that capsule the whole system's shot to pieces. With that outfit, if we should get separated, you can talk to us--we're both wearing 'em, although somewhat different forms. You don't need to talk loud--just a mutter will be enough. They're handy little outfits, almost impossible to find, and capable of a lot of things." "Thanks, Conway--I'll remember that, too," Clio replied, as she turned toward the tiny locker to follow his instructions. "But won't the scouts and patrols be catching us pretty quick? The operator sent a warning." "Afraid the ether's empty, as far as we're concerned. They could neutralize our detector screens, and the scouts' detectors are the same as ours." Captain Bradley had stood by in silent astonishment during this conversation. His eyes had bulged slightly at Costigan's "we're both wearing 'em," but he had held his peace and as the girl disappeared a look of dawning comprehension came over his face. "Oh, I see, sir," he said, respectfully--far more respectfully than he had ever before addressed a mere first officer. "Meaning that we both _will be_ wearing them shortly, I assume. 'Service Specials'--but you didn't specify exactly _what_ Service, did you?" "Now that you mention it, I don't believe that I did," Costigan grinned. "That explains several things about you--particularly your recognition of Vee-Two and your uncanny control and speed of reaction. But aren't you...."