〃What if we open it up and it's just a lot of rusted junk inside； and nothing valuable or enlightening at all？〃
〃Good point；〃 Ted said。
〃Nine hundred fifty feet。 Exterior lights are on；〃 the pilot said。
Through the porthole they saw white flecks。 The pilot explained this was suspended matter in the water。
〃Visual contact。 I have bottom。〃
〃Oh； let's see！〃 Ted said。 The pilot obligingly shifted to one side and they looked。
Norman saw a flat； dead； dull…brown plain stretching away to the limit of the lights。 Blackness beyond。
〃Not much to look at right here； I'm afraid；〃 the pilot said。
〃Surprisingly dreary；〃 Ted said； without a trace of disappointment。 〃I would have expected more life。〃
〃Well； it's pretty cold。 Water temperature is； ah； thirty…six degrees Fahrenheit。〃
〃Almost freezing；〃 Ted said。
〃Yes； sir。 Let's see if we can find your new home。〃
The motors rumbled。 Muddy sediment churned up in front of the porthole。 The sub turned； moved across the bottom。 For several minutes they saw only the brown landscape。
Then lights。 〃There we are。〃
＇＇52＇＇ A vast underwater array of lights； arranged in a rectangular pattern。
〃That's the grid；〃 the pilot said。
The submarine planed up； and glided smoothly over the illuminated grid； which extended into the distance for half a mile。 Through the porthole； they saw divers standing on the bottom； working within the grid structure。 The divers waved to the passing sub。 The pilot honked a toy horn。
〃They can hear that？〃
〃Oh sure。 Water's a great conductor。〃
〃My God；〃 Ted said。
Directly ahead the giant titanium fin rose sharply above the ocean floor。 Norman was pletely unprepared for its dimension； as the submarine moved to port； the fin blocked their entire field of view for nearly a minute。 The metal was dull gray and； except for small white speckles of marine growth； entirely unmarked。
〃There isn't any corrosion；〃 Ted said。
〃No； sir；〃 the pilot said。 〃Everybody's mentioned that。 They think it's because it's a metal…plastic alloy； but I don't think anybody is quite sure。〃
The fin slipped away to the stern； the submarine again turned。 Directly ahead； more lights； arranged in vertical rows。 Norman saw a single cylinder of yellow…painted steel； and bright portholes。 Next to it was a low metal dome。
〃That's DH…7； the divers' habitat； to port；〃 the pilot said。 〃It's pretty utilitarian。 You guys are in DH…8； which is much nicer； believe me。〃
He turned starboard； and after a momentary blackness； they saw another set of lights。 ing closer； Norman counted five different cylinders； some vertical； some horizontal； interconnected in a plex way。
〃There you are。 DH…8； your home away from home；〃 the pilot said。 〃Give me a minute to dock。〃
Metal clanged against metal； there was a sharp jolt； and then the motors cut off。 Silence。 Hissing air。 The ＇＇53＇＇ pilot scrambled to open the hatch； and surprisingly cold air washed down on them。
〃Airlock's open； gentlemen；〃 he said； stepping aside。 Norman looked up through the lock。 He saw banks of red lights above。 He climbed up through the submarine； and into a round steel cylinder approximately eight feet in diameter。 On all sides there were handholds； a narrow metal bench； the glowing heat lamps overhead； though they didn't seem to do much good。
Ted climbed up and sat on the bench opposite him。 They were so close their knees touched。 Below their feet； the pilot closed the hatch。 They watched the wheel spin。 They heard a clank as the submarine disengaged； then the whirr of motors as it moved away。
Then nothing。
〃What happens now？〃 Norman said。
〃They pressurize us；〃 Ted said。 〃Switch us over to exotic…gas atmosphere。 We can't breathe air down here。〃
〃Why not？〃 Norman said。 Now that he was down here； staring at the cold steel walls of the cylinder； he wished he had stayed awake for the briefing。
〃Because；〃 Ted said； 〃the atmosphere of the Earth is deadly。 You don't realize it； but oxygen is a corrosive gas。 It's in the same chemical family as chlorine and fluorine； and hydrofluoric acid is the most corrosive acid known。 The same quality of oxygen that makes a half…eaten apple turn brown； or makes iron rust； is incredibly destructive to the human body if exposed to too much of it。 Oxygen under pressure is toxic…with a vengeance。 So we cut down the amount of oxygen you breathe。 You breathe twenty…one percent oxygen at the surface。 Down here； you breathe two percent oxygen。 But you won't notice any difference…〃
A voice over a loudspeaker said； 〃We're starting to pressurize you now。〃
〃Who's that？〃 Norman said。
〃Barnes；〃 the voice said。 But it didn't sound like Barnes。 It sounded gritty and artificial。
〃It must be the talker；〃 Ted said； and then laughed。 His ＇＇54＇＇ voice was noticeably higher…pitched。 〃It's the helium； Norman。 They're pressurizing us with helium。〃
〃You sound like Donald Duck；〃 Norman said； and he laughed； too。 His own voice sounded squeaky； like a cartoon character's。
〃Speak for yourself； Mickey；〃 Ted squeaked。
〃I taut I taw a puddy tat；〃 Norman said。 They were both laughing； hearing their voices。
〃Knock it off； you guys；〃 Barnes said over the inter。 〃This is serious。〃
〃Yes； sir； Captain；〃 Ted said； but by now his voice was so high…pitched it was almost unintelligible； and they fell into laughter again； their tinny voices like those of schoolgirls reverberating inside the steel cylinder。
Helium made their voices high and squeaky。 But it also had other effects。
〃Getting chilled； boys？〃 Barnes said。
They were indeed getting colder。 He saw Ted shivering； felt goosebumps on his own legs。 It felt as if a wind were blowing across their bodies…except there wasn't any wind。 The lightness of the helium increased evaporation； made them cold。
Across the cylinder； Ted said something； but Norman couldn't understand Ted at all any more； his voice was too high…pitched to be prehensible。 It was just a thin squeal。
〃Sounds like a couple of rats in there now；〃 Barnes said； with satisfaction。
Ted rolled his eyes toward the loudspeaker and squeaked something。
〃If you want to talk； get a talker；〃 Barnes said。 〃You'll find them in the locker under the seat。〃
Norman found a metal locker； clicked it open。 The metal squealed loudly； like chalk on a blackboard。 All the sounds in the chamber were high…pitched。 Inside the locker he saw two black plastic pads with neck straps。
〃Just slip them over your neck。 Put the pad at the base of your throat。〃
〃Okay；〃 Ted said； and then blinked in surprise。 His voice sounded slightly rough； but otherwise normal。
＇＇55＇＇ 〃These things must change the vocal…cord frequencies；〃 Norman said。
〃Why don't you guys pay attention to briefings？〃 Barnes said。 〃That's exactly what they do。 You'll have to wear a talker all the time you're down here。 At least； if you want anybody to understand you。 Still cold？〃
〃Yes；〃 Ted said。
〃Well； hang on； you're almost fully pressurized now。〃 Then there was another hiss； and a side door slid open。 Barnes stood there； with light jackets over his arm。 〃Wele to DH…8；〃 he said。
DH…8
〃You're the last to arrive；〃 Barnes said。 〃We just have time for a quick tour before we open the spacecraft。〃
〃You're ready to open it now？〃 Ted asked。 〃Wonderful。 I've just been talking abou