‘Good Lord!’ said Frank Gresham, ‘what in heaven’s name is that?’
‘Simply,’ continued Mr Rupert, still operating the keys of the machine and apparently writing down what he was saying as he went along, ‘that Mr Manson must have heard, at a later date, about the second entrance to your pumping-room without actually noticing it consciously. It was his subconscious mind that noticed it; and it was his subconscious mind that spoke out under the influence of gas.’
Seff, a whisky glass now planted conspicuously before him, was sketching something. After a few rapid strokes of his pen he skidded the drawing across the table to Manson. ‘Alec,’ he said. ‘Look at that layout. Recognize it? It’s the pumping-room. Take a good look and tell me this: if you had come in through the door marked “A” the cocks would have been on your left; and if you’d come through “B” they would have been on your right. Which side were they?’
Manson saw from the sketch that Seff had deliberately not marked which was the right one and which was the wrong one. It was a memorable moment as Manson stared mutely at the piece of paper, then back at Seff, knowing how much depended on his answer. Then he shut his eyes for a few seconds, and groped with his hands as if he were actually in the pumping-room once more. Eventually he was satisfied, and pushed the sketch back across the table, never taking his eyes off Seff s face. ‘They were on the left,’ he said. No one breathed.
Seff sipped some of the whisky. ‘When I told you to open the outlet valve — which I referred to as the “second cock from the door” — I naturally thought you would go down the quickest way. That is, by the inner stairs. The way Ed went down. Did you see Ed?’
‘No,’ said Manson in a level voice. ‘I didn’t see anyone. Don’t forget, only the emergency lighting was on by then.’
‘That’s right; it was. And there was steam coming from the burst heat exchanger, so I grant you it was difficult to see anything much. And that steam was very radioactive. But I couldn’t afford to think about your personal safety then, or Ed’s — or mine, for that matter. I had to go through the steam myself after discharging some of the cartridges. But, for the present, I want you to recall the moment when we were all on the top of the pile, just before you and Ed went down.’
The Director interrupted. ‘I’m sorry, Seff. But is this relevant? We must get back to Simmel on the radio. Can’t you just tell us, from what Manson has already told you, whether he did turn the right cock?’
‘I think you will see in a minute, Sir Robert, that this is of vital importance.’
‘Then please continue.’
‘As I said,’ continued Seff, ‘our own personal safety had to come second to that of the many employees who were at Marsdowne that night. My job was therefore to prevent a major fire. So I sent Ed down to the cooling-room with instructions to step up the carbon-dioxide pressure, and you to the pumping-room to get rid of the water in the heat-exchange system. If you remember, we had no remote control by then, and everything had to be done manually.’
‘I am not likely to forget it,’ said Manson. And once again the accusation was there.
‘Quite. Now let us consider what you are alleged to have said under the anaesthetic. You said: ‘The second one, yes. But, oh God! From which end?’ Now, why should you have been bothered about “which end”? There could be no doubt, surely — provided you did what you knew I had meant you to do and went down the inner stairs and through the control-room?’
Manson found his lips had gone dry. ‘I don’t see where this is all leading,’ he said.
‘I think you will in a minute. But first you must allow me to make a rather unpleasant suggestion concerning what you might have done — rather in the manner that you suggested what I might have done in my drunken effort to get the pile to react. Have you any objection?’
Manson said: ‘I have no objection to a hypothetical suggestion.’
‘Good. That’s a very good phrase — hypothetical suggestion! It keeps it all nice and friendly, doesn’t it! Well, supposing this is what happened. Supposing you were thrown into complete panic when things started to go wrong. You knew there must have been a hell of a lot of radiation about — particularly on the inner stairs, which run right underneath the heat exchangers. You were terrified, in fact. So you rushed out of the main hall, went through the air-lock, and into the pumping-room through the other entrance. The wrong entrance, Manson! And when you got there you were in such a panic that you couldn’t work out for a moment which cock you should have turned, having come through the wrong door! You weren’t in any real doubt as to which door I meant you to use. So what you said under the anaesthetic was not an expression of doubt that you felt after the event, but your panic-stricken feeling at the moment of entering the pumping-room!’
‘A very interesting and incriminating hypothesis,’ said Manson calmly. ‘Only it doesn’t work, because I told you that the cocks were on the left. Which they obviously couldn’t have been if I had come through the other door.’
‘My dear chap,’ said Seff with grim bonhomie, ‘I didn’t ask you that question merely to get the right answer. After all, you’ve had two years to think it out.’ There were about one thousand roentgens of tension in the air now.
‘Then why,’ said Manson stupidly, ‘did you ask me?’
Seff knocked back the rest of the Scotch. ‘To get you to lie,’ he said, and his eyes had become rivets. ‘You’re a fool, Manson. If you had told me you came down the wrong stairs, if you had told me the cocks were on the right, and therefore you turned the first one instead of the second, you would have got away with it. But don’t you see what you have forgotten?’
He took something out of his brief-case and put it on the table. It was a large chart, and he spread it across the table, using ash-trays as weights. ‘I got this from Ed’s office this morning,’ he said. ‘As you see, it’s the Lifetime Dose Sheet for that period. If Ed had a more suspicious mind, he might have realised that the answer to this whole bloody business had been staring him in the face the whole time.’
Manson found that the muscles of his face had become so stiff that he couldn’t move his lips properly. But he managed to say, in a voice that was almost steady: ‘I don’t see what the Dose Sheets have got to do with it.’ And, more confidently: ‘In any case, Springle wasn’t with Administration at the time.’
Seff looked at him expressionlessly. ‘You’re right; nor he was. So why should he have got curious? I only thought of it myself a few minutes ago, when there was some reason to. And I had to make a special journey to get the sheets.’
Manson felt the panic building inside him — the more so because he couldn’t see what significance the information stored on those bits of paper could have. But he said: ‘I hope it’s good, Seff. Because after what you’ve said to me it had better be!’ He paused for a moment, found that Mr Rupert was staring at him from the end of the table, his fingers poised over the keyboard in readiness. Manson wrenched his eyes away, turned back to Seff. ‘Well? What do you fondly suppose you’ve discovered?’
‘Take a look, my friend. I think you’ll find it rather interesting. Here we are — you see the red entries? There’s mine — I got 40 roentgens that night. A pretty stiff dose, but nothing to Ed’s; he got nearly 60! Of course he did; he had to come down the inner stairs. He knew it was vital to turn on the gas, and he risked his life to do it. Now look at yours, Manson. Just over 6 roentgens. Now, tell me how you managed to get down the inner stairs and get off so lightly? Just how hypothetical is that?’