“In?” said Arthur in horror.

“Into the interior of the planet! An underground passage. The force of the whale’s impact cracked it open, and that’s where we have to go. Where no man has trod these five million years, into the very depths of time itself…”

Marvin started his ironical humming again.

Zaphod hit him and he shut up.

With little shudders of disgust they all followed Zaphod down the incline into the crater, trying very hard not to look at its unfortunate creator.

“Life,” said Marvin dolefully, “loathe it or ignore it, you can’t like it.”

The ground had caved in where the whale had hit it revealing a network of galleries and passages, now largely obstructed by collapsed rubble and entrails. Zaphod had made a start clearing a way into one of them, but Marvin was able to do it rather faster. Dank air wafted out of its dark recesses, and as Zaphod shone a torch into it, little was visible in the dusty gloom.

“According to the legends,” he said, “the Magratheans lived most of their lives underground.”

“Why’s that?” said Arthur. “Did the surface become too polluted or overpopulated?”

“No, I don’t think so,” said Zaphod. “I think they just didn’t like it very much.”

“Are you sure you know what you’re doing?” said Trillian peering nervously into the darkness. “We’ve been attacked once already you know.”

“Look kid, I promise you the live population of this planet is nil plus the four of us, so come on, let’s get on in there. Er, hey Earthman…”

“Arthur,” said Arthur.

“Yeah could you just sort of keep this robot with you and guard this end of the passageway. OK?”

“Guard?” said Arthur. “What from? You just said there’s no one here.”

“Yeah, well, just for safety, OK?” said Zaphod.

“Whose? Yours or mine?”

“Good lad. OK, here we go.”

Zaphod scrambled down into the passage, followed by Trillian and Ford.

“Well I hope you all have a really miserable time,” complained Arthur.

“Don’t worry,” Marvin assured him, “they will.”

In a few seconds they had disappeared from view.

Arthur stamped around in a huff, and then decided that a whale’s graveyard is not on the whole a good place to stamp around in.

Marvin eyed him balefully for a moment, and then turned himself off.

Zaphod marched quickly down the passageway, nervous as hell, but trying to hide it by striding purposefully. He flung the torch beam around. The walls were covered in dark tiles and were cold to the touch, the air thick with decay.

“There, what did I tell you?” he said. “An inhabited planet. Magrathea,” and he strode on through the dirt and debris that littered the tile floor.

Trillian was reminded unavoidably of the London Underground, though it was less thoroughly squalid.

At intervals along the walls the tiles gave way to large mosaics—simple angular patterns in bright colours. Trillian stopped and studied one of them but could not interpret any sense in them. She called to Zaphod.

“Hey, have you any idea what these strange symbols are?”

“I think they’re just strange symbols of some kind,” said Zaphod, hardly glancing back.

Trillian shrugged and hurried after him.

From time to time a doorway led either to the left or right into smallish chambers which Ford discovered to be full of derelict computer equipment. He dragged Zaphod into one to have a look. Trillian followed.

“Look,” said Ford, “you reckon this is Magrathea…”

“Yeah,” said Zaphod, “and we heard the voice, right?”

“OK, so I’ve bought the fact that it’s Magrathea—for the moment. What you have so far said nothing about is how in the Galaxy you found it. You didn’t just look it up in a star atlas, that’s for sure.”

“Research. Government archives. Detective work. Few lucky guesses. Easy.”

“And then you stole the Heart of Gold to come and look for it with?”

“I stole it to look for a lot of things.”

“A lot of things?” said Ford in surprise. “Like what?”

“I don’t know.”

“What?”

“I don’t know what I’m looking for.”

“Why not?”

“Because… because… I think it might be because if I knew I wouldn’t be able to look for them.”

“What, are you crazy?”

“It’s a possibility I haven’t ruled out yet,” said Zaphod quietly. “I only know as much about myself as my mind can work out under its current conditions. And its current conditions are not good.”

For a long time nobody said anything as Ford gazed at Zaphod with a mind suddenly full of worry.

“Listen old friend, if you want to…” started Ford eventually.

“No, wait… I’ll tell you something,” said Zaphod. “I freewheel a lot. I get an idea to do something, and, hey, why not, I do it. I reckon I’ll become President of the Galaxy, and it just happens, it’s easy. I decide to steal this ship. I decide to look for Magrathea, and it all just happens. Yeah, I work out how it can best be done, right, but it always works out. It’s like having a Galacticredit card which keeps on working though you never send off the cheques. And then whenever I stop and think—why did I want to do something?—how did I work out how to do it?—I get a very strong desire just to stop thinking about it. Like I have now. It’s a big effort to talk about it.”

Zaphod paused for a while. For a while there was silence. Then he frowned and said, “Last night I was worrying about this again. About the fact that part of my mind just didn’t seem to work properly. Then it occurred to me that the way it seemed was that someone else was using my mind to have good ideas with, without telling me about it. I put the two ideas together and decided that maybe that somebody had locked off part of my mind for that purpose, which was why I couldn’t use it. I wondered if there was a way I could check.

“I went to the ship’s medical bay and plugged myself into the encephelographic screen. I went through every major screening test on both my heads—all the tests I had to go through under government medical officers before my nomination for Presidency could be properly ratified. They showed up nothing. Nothing unexpected at least. They showed that I was clever, imaginative, irresponsible, untrustworthy, extrovert, nothing you couldn’t have guessed. And no other anomalies. So I started inventing further tests, completely at random. Nothing. Then I tried superimposing the results from one head on top of the results from the other head. Still nothing. Finally I got silly, because I’d given it all up as nothing more than an attack of paranoia. Last thing I did before I packed it in was take the superimposed picture and look at it through a green filter. You remember I was always superstitious about the color green when I was a kid? I always wanted to be a pilot on one of the trading scouts?”

Ford nodded.

“And there it was,” said Zaphod, “clear as day. A whole section in the middle of both brains that related only to each other and not to anything else around them. Some bastard had cauterized all the synapses and electronically traumatised those two lumps of cerebellum.”

Ford stared at him, aghast. Trillian had turned white.

“Somebody did that to you?” whispered Ford.

“Yeah.”

“But have you any idea who? Or why?”

“Why? I can only guess. But I do know who the bastard was.”

“You know? How do you know?”

“Because they left their initials burnt into the cauterized synapses. They left them there for me to see.”

Ford stared at him in horror and felt his skin begin to crawl.

“Initials? Burnt into your brain?”

“Yeah.”

“Well, what were they, for God’s sake?”

Zaphod looked at him in silence again for a moment. Then he looked away.

“Z.B.,” he said.

At that moment a steel shutter slammed down behind them and gas started to pour into the chamber.

“I’ll tell you about it later,” choked Zaphod as all three passed out.