'Two plus David Masen makes three.'

'But the sheer sweat and effort it took to get David away from Torrence... You'd have to be mad to send him back there.'

Sam smiled. 'Welcome to the lunatic asylum, Gabe.'

'But for crying out loud, why? If David falls into Torrence's hands we're back where we started. Worse. Torrence will lock David away until he can use him as a hostage to get hold of the Isle of Wight and that hoo-hah machine that turns triffid oil into aviation fuel, gasoline and a whole lot else. Then we're all dead and buried.'

Sam knitted his fingers together. 'Needs must, Gabe. We need to spring Christina from New York. As well as those fifty Marines we need engineers and sappers with demolition expertise. That makes a force of ninety.'

'So they can be carried in two planes, not three.'

Sam turned to me. 'I'm no flyer, David. Explain the problem to Gabe.'

'Two planes can carry ninety people between them, but the more passengers or payload you carry the faster you use fuel. You need to split those ninety people between three planes for that kind of distance or you'd simply run out of fuel on the return journey.'

'Then fly in a pilot from another base.'

'You know that's impossible, Gabe,' Sam told him. 'They're overstretched as it is.'

Gabriel accepted this with an expansive gesture. 'OK. Granted. Even disregarding that I think we're crazy to send David back into the lions' den, there are still fundamental problems. One. We don't know where Christina Schofield is being held.'

'We do: the Empire State Building. Ninety-third floor.'

'So you found a replacement for me on the inside fast enough?'

'He or she,' Sam replied cagily, 'was already in place. You were the best, but we needed to know we had a substitute.'

'Just in case?'

Sam admitted it with a nod. More coffee appeared on the table; Sam lit a cigarette. And so the talking went on throughout the afternoon. Outside the meagre sun did its best to illuminate the world. A flock of geese flapped steadily southwards overhead, their honking cries filling the air. Beyond the fence, evicted triffids rattled their sticks, twitched their leaves and did their best to flaunt their sinister presence.

One by one the points of Sam's plan were worked through. Fuel requirements. The range of the aircraft. Their capacity to hold demolition explosives. Types of ammunition. Food rations. Duration of mission. Route. And so on. It was the real nitty-gritty where the devil was truly in the detail. For a tiny item overlooked could result in a catastrophic failure of the whole strategy.

I confess. During a lengthy debate between Sam and Lieutenant Truscott on whether hollow-point or solid-point ammunition should be used my mind wandered. As they talked I made a series of little sketches on a bit of paper I found under the table.

There was a break for sandwiches and the roast beef that had been flown in that morning made its appearance between slices of bread. The respite from fish-and-triffid stew was enough to lift spirits a little at least.

Reconvening the briefing meeting, Gabriel raised the problem of what he considered was an insurmountable obstacle to any progress we could make with the plan. 'Radar,' he said. 'New York is protected from every point of the compass by an extensive network of radar stations. How do the aircraft approach the place undetected?'

I raised a finger. 'I've been putting some thought into that one,' I said. 'Firstly, we have to make our approach at night. There's a half-moon over the next few days that should be enough for us to see by.'

'OK.' Gabriel shrugged. 'We fly in by the beautiful light of the silvery moon. But radar can detect us as easily by night as it can by day.'

'This is the tricky bit,' I told him. 'To avoid detection by radar we need to fly in at a very low altitude. Probably no more than a hundred feet.'

'But even flying that low over open water still won't be enough for us to escape radar detection, will it?'

'No. Like I said, this is the tricky part.' I placed my roughly sketched map on the table. 'That's Manhattan Island. Running north from it is the Hudson River. If I remember correctly the Hudson is flanked by steep hills and cliffs over a hundred feet high. We need to fly down the river, keeping below the tops of the cliffs.' I pointed at my map. 'That's the only way we can reach New York without being detected by its radar.'

This time it was one of the pilots who all but choked on his disbelief at my suggestion. 'This is crazy. You're seriously telling us that we have to fly a big four-engine plane along a river valley just a hundred feet above the water? And in the dark?'

'It can be done.'

'It's suicide.'

'We'll make it.'

'But an altimeter isn't accurate at that low an altitude. How can you judge that you're just a hundred feet above the surface?'

I put sketch number two on the table. 'We fix small lights on either wing. Here, on the port and starboard float struts. If you point these downward at a carefully calculated angle, the focused light beams will fall on the water, showing as two spots of light. In a mirror set against the cockpit window the navigator will see these spots of light gradually move closer to one another as the plane descends. As I've said, these lights will be precisely angled. And, giving the pilot a continuous commentary, the navigator will sing out when the two spots of light merge into one on the surface of the water.' I tapped the paper with my fingertips. 'At that point - with the convergence of the lights - that's when the plane will be travelling precisely one hundred feet above the water. Which will be low enough to get us under New York's radar without being detected.'

Sam clapped his hands together. And that, ladies and gentlemen, is how David Masen has just earned his keep.' He turned to me. 'Now, David. Added to my congratulations on your invention - let's call it-' he gave a wry smile '-the Masen Height Indicator - is my suggestion that you start work on it straightaway. We leave for New York in two days.'

CHAPTER THIRTY THREE.

NIGHT JOURNEY.

WHETHER the following words come from a song, a play, a folk legend or are some ancient Oriental proverb I just don't know: Softly, softly, catchee monkey!

The words, however, ran freely and unbidden through my head as the three flying boats lifted from the smooth surface of the river before turning northwards for the three-hour flight to New York.

Softly, softly, catchee monkey! A proverb (if it was a proverb) that urged stealth, and perhaps a certain delicacy of action, if you wanted to catch your primate. For, as I raised the nose of the aircraft, the engines humming sweetly in my ears, I knew that I had an ulterior motive for making sure that I was piloting one of the New York-bound planes. When I arrived there I would find Kerris Baedekker. Then I would take her to my homeland. You must understand that it was as though this conviction had embedded itself in every nerve, sinew and bone of my body. I knew I would rescue her. We would be reunited.

But, to be completely candid, it was how I would achieve this outcome that completely mystified me.

Softly, softly, catchee monkey! Naturally, no one else knew of my plan. A poor half-formed plan at that.

'Coffee?'

'Please.' A co-pilot was a luxury the mission could not afford so Gabriel Deeds occupied the seat beside me. He poured steaming coffee from a thermos.

'So far, so good?' he asked, handing me the cup.

'So far, so good,' I agreed. 'And now comes the magical part that passengers prefer not to think about.' I flicked a switch on the control panel in front of me. Then I took my hands off the joystick.

Watching a little uneasily as the joystick continued to respond as if to a ghostly controlling hand, Gabriel said, 'Automatic pilot?'

'The pilot's best friend.' I smiled. 'Now I can go and get some shut-eye until we're ready to land.'

Gabriel's eyes widened.

'I'm kidding, Gabe. I'll stay here in the hot seat, but at least I can relax - well, try to relax - for a while.' I sipped the coffee.

'Quite some sunset.' Gabriel nodded through the window at the flaming reds and golds bursting on the horizon. 'But I'd prefer it if I was watching it with the ground beneath my feet.'

'Not down there. That's triffid country. Just look at the beggars. There must be thousands.'

He swallowed. 'I'd still rather take my chances down there.'

'You're not a devotee of air travel, then?'

In a rather dry voice he said, 'First time I've ridden in a cockpit.'

'Don't worry... in ten minutes you'll get used to it. In half an hour you'll love it. In two hours you'll be bored stiff.'

He nodded. The look in his eye, however, told me loud and clear that he didn't believe one word.

I turned back to the navigator. 'How're we doing?'

'Right on course. Before it gets dark the planes will switch on their tail lights. The leader will show a green tail light. The middle plane will display a blue one. Follow the blue.'

'OK.' I returned to gaze through the window as mainland America rolled out beneath me in a carpet of green. A green, I knew, that contained the sinister dark hues of triffid leaves. Masters of their territory, they would be settling for the night, their roots anchored firmly into soil that was once part of fields, parks and gardens. I could see them in my mind's eye. On top of their stems the cones would detect the sound of our planes passing high overhead. The cones would move as one, tracking the source of the sound. Perhaps the finger sticks would rattle. They'd be comparing notes with a triffid neighbour or sending a message that would alert farther-flung comrades.

Although I could see perhaps thirty miles there were none of the tell-tale smoke trails that would indicate human occupation. Down there the triffid was king.

Even though the hydraulic system of the autopilot kept the plane efficiently in trim while maintaining an economical two hundred miles per hour, my eyes would repeatedly flick to the gauges, checking altitude, airspeed and so on. A little ahead of me I could see the other two planes in our formation. Wings glinted gold in the setting sun. To a seasoned pilot like myself it made for a heart-warming sight.

This part of the flight would - gods of the air willing - be reasonably straightforward. Landing undetected near the island of Manhattan would be another matter entirely. With the help of a pair of electricians I had rigged up the light system that Sam Dymes had jokingly named the Masen Height Indicator. Test flights over the river showed that it did work. Thankfully. Because in a couple of hours we were going to have to put it to the test.

Gabriel must have become a little more accustomed to flying because he unbuckled his seat belt, commenting that he was going back to check on our passengers. These consisted of twenty Marines, the elite troops of the Foresters' army, along with an eight-strong team made up of sappers who were expert in demolition (their huge store of plastic explosives was crammed in the forward hold), a couple of radio communications technicians and, for some reason, a television engineer. While an expert in televisual broadcasting did seem a mystifying requirement to me, I guessed Sam Dymes simply wouldn't have been so frivolous that he'd asked the lady along just for the ride.

These planes had been built to transport civilian passengers in some degree of comfort. They certainly hadn't been intended as troop carriers. So for now our passengers could enjoy the benefits of electric-razor points, hot and cold water and well-appointed 'bathrooms' - as the Americans called toilets - with a similarly well-equipped galley that boasted hot plates, a toaster and thermos compartments for hot meals. If any of them had the stomach for food, that was. For the previous night I'd seen those men and women writing letters that would be delivered to their families if they should fail to return from the mission.

Gabriel returned with the news that our passengers were in good shape. Many were fast asleep, although how they could sleep at a time like this was beyond me.

Beyond the windows the sky darkened quickly as night fell. Whatever had dimmed the stars and the sun had affected the moon similarly. Certainly it wasn't as bright as it should have been. It showed itself as an orange semicircle above my port wing.

I glanced at Gabriel. He was taking a more objective interest in the business of flying now. I noticed his dark eyes flicking from the artificial horizon to the airspeed indicator, then to the altimeter. His quick mind made sense of the apparent confusion of dials.

'Do you fancy having a go, Gabe?' I asked, nodding at the joystick in front of him. 'It's fairly straightforward.'

'I'll leave it to you this time round.' He smiled. 'To tell you the truth, the thought of all that explosive down in the hold is making me a mite nervous.'

'Thoughts about it keep popping up in my mind, too. Either that or the fifteen tons of fuel we've got stuffed into the tanks... So I hope no one's calming their nerves with a cigarette back there.'

Gabriel's smile looked a tad more forced. 'I hope so, too.'

I voiced something that had been on my mind. 'I hear Sam Dymes is in the lead plane. I thought that, as commander of the camp, he'd have stayed behind?'

'Top brass are pushing hard for this mission to be one hundred per cent successful. I'm not belittling the skills of those guys in the back but Sam knows he has to put everything he's got into this one.'

'You know, Gabe, I've been thinking...'

'Oh?' He gave me a sideways glance.

'There's a few details about this mission that have been nagging away at me.'

'It's going to be a tough one. No doubting that.'

'I know the prime objective is to spirit Christina Schofield away from Torrence.'

'That's it in a nutshell.'

'But the Foresters aren't thinking of breeding their own super-race, are they? After all, if you have people who are immune to triffid poison then you're going to have the edge over everyone else.'

True. But we're not going to do anything as radical as remove her ovaries and then implant our womenfolk with the eggs.'

'Really?'

'Do I detect a note of disbelief, David?'

'Maybe after my experiences of the last couple of months I'm becoming a more suspicious person.'

'David, our community prides itself on its humanity. That's why we split with Torrence's junta in the first place.'

I gazed out at the coloured tail lights of the other two planes. 'But surely the same thought must have gone through the minds of your leaders. I imagine that they've required Sam to come up with some contingency plan, too.'

'And what would that be?'

'That it would be in the interests of national security that if Christina couldn't be rescued then she should be killed. And her body destroyed so that her ovaries would be useless.'

Gabriel's expression hardened. 'You think Sam Dymes would be capable of something as brutal as that?'

'Desperate times call for desperate measures. You know that, Gabe.'

'You are developing a suspicious streak, David.'

'I agree. But right now I'd describe that as a useful survival trait.'

'Oh?'

'Maybe being entrusted with piloting this plane to New York has given me more confidence in my own position among your people, and maybe I'm saying more than I ought. But it occurs to me that it would make perfect sense to order the Marines to ensure that I didn't fall into Torrence's hands under any circumstances.'

'You really think we'd do that to you?'

I shrugged. 'What I do think is that it would be very wise to make damn sure I took a bullet in the head rather than become Torrence's hostage.' I looked at Gabriel. 'After all, I remember that when I was snatched from New York there was a contingency plan if it seemed my rescue might be in doubt.'

'That is perfectly correct.' Gabriel nodded slowly. 'All I can say is, trust us: we'll keep you safely out of harm's way once we're in New York.'

'That's not going to be easy.'