Everyone in the salon, of course, wore a Helmet—even the Man in the Moon, under his disguise. Cumbersome as they looked, they rested lightly on the wearers’ shoulders, and were actually so light that one easily became accustomed to them. Andrea studied her reflection in a nearby mirror. Her small, heart-shaped face seemed dwarfed by the Helmet. Experimentally, like an interested child, she pressed a stud and saw the transparent, air-tight shield slide into place an inch from her nose. Within the ship the shields were not necessary, nor were complete space-suits. But the Helmets were vital. * * * * * Andrea knew little or nothing of the technical details. The secret of the Helmets lay in the luminous, intertron knob atop each one. It was this that provided a two-way hook-up with the Varra. She remembered what an officer had told her, when she had first donned a Helmet at the Atlantic Spaceport. “Never done it before, eh, miss? Well, don’t be frightened. Let me help you.” He had adjusted the bulky Helmet. “The power won’t be turned on till we hit the Heaviside Layer. The Varra can’t safely enter our atmosphere, you know.” “I didn’t know. It seems so strange—” The officer chuckled. “Not really. It’s like being in radio communication with somebody. You see, when the juice is turned on, a Varra instantly hooks itself up to your Helmet. You can even talk to him—it—if you like. They’re intelligent; nice people, in fact.” “Can they read thoughts?” “Everybody asks me that. No, they can’t. The idea is that without a Helmet, you’d be exposed to the Plutonian mind-vampires. As it is, the Varra throws up a mental shield that protects you.” Andrea hesitated. “It doesn’t always work, though, does it?” “Almost always. You were warned of that—” His manner became officially rigid. “You signed a release blank, in case of accident. But there’s no danger to speak of. Space flight is exhausting; you’ll feel pretty bad by the time we hit Mars. Somehow there’s an energy drain that even the Varra can’t neutralize.” “The Plutonians?” “We think so. But without the Helmets—” He grinned in a comforting fashion. “You’ll be okay, miss.” Later, at the Heaviside Layer, the power had been turned on in each Helmet. There was no apparent change, except for the sudden luminosity of the intertron knobs. But a voice, friendly despite its curious alienage, had spoken wordlessly inside Andrea’s brain. “I’m taking over now. Don’t remove your Helmet or turn off the power till you’re in atmosphere again.” “Atmosphere—” Andrea had spoken aloud without realizing it. The Varra answered her. “Each planet has a Heaviside Layer, an electronic barrage that disrupts mental-energy vibrations. We find it dangerous to pass that Layer, but so do the Plutonians.”