`You seem so certain.'

`I'm not certain. I'm just worried.'

Nordmann raised an eyebrow. `A triple whammy?'

`Maybe.'

`I think you're giving him too much credit.'

`Maybe.'

Graves continued to prowl around the room.

`Well,' Nordmann said, `in the meantime I think we'd better move these tanks apart. Just in case. I'll be happier when they're separated by a distance of several miles.'

`Okay,' Graves said. He was hardly paying attention, looking at the equipment in the room. `You know,' he said, `I can't get over the feeling that it's been too simple.'

`Too simple? It's been complicated as hell.' Nordmann put his arm over Graves' shoulder. `I think you're tired,' he said gently.

Across the room Lewis said, `It's five o'clock, gentlemen.' Everyone, including the cops, laughed. One or two of the men in the room clapped.

On the floor the timer wheel clicked once. There was a loud metallic snap.

The battery light blinked on.

The twin solenoids clicked to the `open' position.

And nothing happened, because the solenoids had been disengaged from the tanks.

`Well,' Nordmann said, `I can't imagine that there's anything else.'

`I guess not,' Graves said.

He and Nordmann left the apartment and walked down the corridor towards the elevators.

HOUR 0

At 5:02 Graves pressed the button for the elevator. The light didn't go on. He looked up at the floor numbers, one of which should have been lighted; they were all dark.

`That's funny,' he said.

Nordmann frowned. `Maybe they went on the blink.' `Why?' Graves asked.

`Maybe when we cut the power to the apartment -' `But they worked before.'

`Yes, that's true. They did.'

`Why should they break down now?'

At that moment a cop came up the stairs, panting heavily. `Damned elevators are broken down,' he said. `We checked the circuit breakers in the basement., There was a timer wired in to knock out the elevators exactly at five.'

`At five?' Graves asked. He looked at Nordmann.

Nordmann shrugged. `Probably just a little irritant he threw in.'

`An irritant? But that doesn't make sense.'

`It's plenty irritating to me,' Nordmann said. `I don't want to walk down nineteen flights of stairs.'

`Of course,' Graves said. `But why do it now?'

`I don't get you.'

`Well, if Wright wanted to make things difficult, he would have knocked out the elevators at four PM. And that would have made things very difficult for us. It might even have delayed us until the gas went off.'

`True.'

`But why wait until five? By then we've either beaten his system or we haven't.'

`Listen,' Nordmann said, `I think you're tired. You've been worrying about Wright for so long -'

`I am not tired,' Graves said, shaking off Nordmann's arm. 'Wright was a logical man, and there is logic in this move.'

`There are no more moves,' Nordmann said. `We've won.'

`Yes,' Graves said. `That's exactly what we're supposed to think.'

And he turned and walked back to the apartment.

`John,' Nordmann said, running to catch up with him. `John, listen -'

`You listen,' Graves said. `What's the point of knocking out the elevators after five?'

`It has no point. It's a foolish irritation.'

`Wrong,' Graves said. `It has one important point. It traps everybody on the nineteenth floor. And it traps the tanks as well.'

`That's true,' Nordmann said. `But it hardly matters. We've disarmed the mechanism.'

`Have we?'

`Oh, for Christ's sake, of course we have. You did it yourself. You know it's disarmed.'

`But what if it's not?'

`How can it not be?'

At that, Graves sighed. `I don't know,' he admitted. He reentered the apartment.

HE OFTEN FEELS THAT A PROBLEM IS SOLVED WHEN

IT IS ONLY HALF FINISHED, OR TWO-THIRDS FINISHED.

Graves remembered the psychological report as he paced the apartment, talking out loud. Nordmann watched him and listened. In the background, cops were disassembling the tank mechanisms.

`All right,' Graves said. `Let's think it through. Wright designed a mechanism.'

`Yes.'

`And the mechanism had a purpose.'

`Yes, to dump nerve gas over the city at five rht.'

Graves nodded. `And we have thwarted that.'

`Yes,' Nordmann said.

`Did he have any other purpose?'

`Well, I don't know. You could answer that better than anyone. Somebody mentioned something about disagreeing with the President over China -'

`No, no,' Graves said. `Let's forget about motivation. Let's consider only the intent of his system. Did he intend to do anything besides dump the nerve gas?'

`Raise hell, create panic…' Nordmann shrugged.

Graves was silent, frowning at the room. `I mean,' he said, `did Wright intend his elaborate mechanism to do anything besides dump the gas?'

`No,' Nordmann said.

`I agree,' Graves said.

There was a long pause. Graves considered everything. he knew, from every angle. He could make no sense of it, but he somehow felt certain that pieces were missing. Vital pieces…

`He knew about you,' Graves said suddenly.

`What?'

`He knew about you. He knew that I had called you in.'

`So what?'

`Why should he care?'

`He didn't care.'

Graves began to see. It was coming into focus. `Because,' he said, 'Wright knew about you. He knew your position, and he knew your expertise. He must have known that you could provide an antidote to the binary gas.

`If he knew you could provide an antidote, then he also knew his protection - filling this room with gas -would not work. We'd break in. He knew that.'

`Are you sure?'

`Yes, I'm sure. And he didn't care.'

`Perhaps he was bluffing,' Nordmann said.

`It's too important for a blur. He must have had another part of his system to cover that eventuality. He must have planned it so that if we did break in, he'd still manage to win.'

Nordmann considered it all very carefully. At length he sighed and shook his head. `I'm sorry, John,' he said, `I think you're entirely wrong about this. You're making hypothetical sand castles in the air -'

`No!' Graves snapped his fingers. `No, I'm not. Because there was a second purpose to his system.'

`What second purpose?'

'Wright was going. to Jamaica, or somewhere, correct?'

`Correct.'

`And he was not suicidal, correct?'

`Correct. He expected to get there.'

`All right. Then that establishes the need for a second purpose. His mechanism had to do two things.'

`What two things?'

`Look,' Graves said. He spoke as rapidly as he could, but he was hardly able to keep pace with his racing mind. 'Wright planned all this and planned it carefully. If he succeeded, a million people would die, including the President. A major political party would be wiped out. There would be national panic of incredible proportions. And for some reason, he wanted that.'

`He was insane, yes…'

`But not suicidal. He planned an escape. And the question is, what about afterwards?'

'Afterwards?'

`Sure. Wright is on some beach sunning himself and gloating as he reads the headlines. But for how long?'

`Damn,' Nordmann said, nodding.

Phelps was also listening. `I don't follow you,' he said.

`You never do,' Graves snapped. `But the point is this. Sooner or later, Navy men in protective suits would enter San Diego. They would determine that people died of nerve gas. They would search for the source. They would find this apartment. They would enter it. They would find the tanks. They would put the pieces together.'

`And they would come after Wright,' Nordmann said.