Andrew was signalling again, urging him to turn back, but Michael gave him a curt flick of the hand, Follow me!'- and threw the Sopwith up on one wingtip, bringing her round in a steep turn that strained her damaged bodywork.

Michael was lost in the raptures of fighting madness, the berserker's wild passion, in which the threat of death or fearful injury was of no consequence. His vision was heightened to unnatural clarity, and he flew the damaged Sopwith as though it were an extension of his own body, as though he were part-swallow skimming the water to drink in flight, so lightly did he brush the hedgerows and touch the stubble in the fields with his single remaining landing wheel, and part-falcon, so cruel was his unblinking gaze as he hated at the ponderously descending balloon.

Of course, they had seen the fiery destruction of the first balloon, and they were winching in. They would be down before Michael reached the site. The gunners would be fully alerted, waiting with finger on the trigger. It would be a ground level attack, into the prepared positions, but even in his suicidal rage, Michael had lost none of the hunter's cunning. He was using every stick of available cover for his approach run.

A narrow country lane angled across the front, the row of slim, straight poplars that flanked it was the only feature on this dreary plain below the ridge. Michael used the line of trees, banking steeply to run parallel with them, keeping them between him and the balloon site, and he glanced up at the mirror fixed to the wing section above his head. Andrew's green Sopwith was so close behind him that the spinning propeller almost touched his rudder. Michael grinned like a shark and gathered the Sopwith in his hands and lifted it over the palisade of poplar trees the way a hunter takes a fence at full gallop.

The balloon site was three hundred yards ahead. The balloon itself had just reached ground level. The ground crew were helping the observers out of the basket and then running in a group for the cover of the. nearest trench. The machine-gunners, their aim frustrated up to that moment by the row of poplar trees, had a fair target at last, and they opened together.

Michael flew into a torrent of fire. It filled the air about him, and the shrapnel shells sucked at the air as they passed, so that his eardrums clicked and ached with the pressure drops. In the emplacements he saw the faces of the gunners turned up towards him; they were pale blobs behind the foreshortened barrels that swung to follow him and the muzzle flashes were bright and pretty as fairy lights. However, the Sopwith was roaring in at well over 100 miles an hour and he had barely 300 yards to cover. Even the solid crunch of bullets into the heavy engine block could distract Michael as he lined up his sights with delicate touches on the rudder bars.

The group of running men escaping from the balloon was directly ahead of him, racing back towards the trench.

In their midst the two observers were slow and clumsy, still stiff with the cold of the upper air, burdened by their heavy clothing. Michael hated them as he might hate a venomous snake, he dropped the Sopwith's nose fractionally and touched the firing lever. The group of men blew away, like grey smoke, and disappeared into the low stubble. Instantly Michael lifted the aim of the Vickers.

The balloon was tethered to earth, looking like a circus tent. He fired into it, bullets streaming on silvery trails of phosphorus smoke into the soft silken mass without effect.

In the berserker's rage, Michael's brain was clear, his thought so swift, that time seemed to run slower and still slower. The micro-seconds as he closed with the stranded silken monster seemed to last an-eternity, so that he could follow the flight of each individual bullet from the muzzle of his Vickers.

Why won't she burn? he screamed the question again, and the answer came to him.

The hydrogen atom is the lightest of all in weight. The escaping gas was rising to mingle with oxygen above the balloon. It was so obvious then, that he was shooting too low. Why hadn't he realized it before?

He hauled the Sopwith up on her tail, streaming his fire upwards across the swelling side of the balloon, still up until he was shooting into empty air, over the top of the balloon, and the air turned to sudden flame. As the great exhalation of fire rolled towards him, Michael kept the Sopwith climbing into the vertical and jerked the throttle closed. Without power she hung for an instant on her nose and then stalled and dropped. Michael kicked hard at the rudder bar, spinning her into the classic stall turn, and as he opened the throttle again he was headed back, directly away from the immense funeral pyre that he had created. Beneath him he caught a green flash as Andrew banked on to his wingtip in a maximum-rate turn, breaking out left, almost colliding with Michael's undercarriage, and then hurtling away at right angles to his track.

There was no more ground fire; the sudden acrobatics of the two attackers and the roaring pillar of burning gas entirely distracted the gunners, and Michael dropped back behind the cover of the poplar trees, Now that it was all over, his rage abated almost as swiftly as it had arisen, and he swept the skies above him, realizing that the columns of smoke would be a beacon for the Albatros Jagdstaffels. Apart from the smoke, the skies were clear, and he felt a lift of relief and looked for Andrew as he banked low over the hedgerows. There he was, a little higher than Michael, already heading back towards the ridges, but angling in to intercept in.

They came together. Strange what comfort there was in having Andrew on his wingtip, grinning at him and shaking his head in mock disapproval of the disobeyed order to return to base and the berserker fit which had seized Michael.

Side by side they roared low across the German front lines again, contemptuous of the splattering of fire they drew and then as they began to climb to cross the ridge, Michael's engine spluttered and lost power.

He dropped towards the chalky earth, and then the engine fired again, bellowed and surged, lifting him just clear of the crest, before missing and banging unevenly once more. Andrew was still beside him, mouthing encouragement, and the engine roared again I and then missed and popped.

Michael nursed it, pumping the throttle, fiddling with the ignition setting, and whispering to the wounded Sopwith. Come on, my darling. Stick it out, old girl. Nearly home, there's my sweetheart. Then he felt something break in her body, one of the main frames shot through, and the controls went soft in his hands, and she sagged, sick unto death. Hold on, Michael exhorted her, but suddenly there was the pungent stink of petrol in his nostrils, and he saw a thin transparent trickle of it ooze from under the engine cowling and turn to white vapour in the slipstream as it blew back past his head.

Fire. It was the airman's nightmare, but the vestiges of rage were still with Michael and he murmured stubbornly, We're going home, old girl. just a little longer. They had crossed the ridges, there was flat terrain ahead, and he could already make out the dark T-shaped wood which marked the approach to the airstrip. Come on, my sweeheart. Beneath him there were men, out of the trenches, lining the parapets, waving and cheering as the damaged Sopwith clattered and popped close above their heads, one of its landing wheels shot away, the other dangling and slamming against its belly.

Their faces were upturned, and he saw their open mouths as they called to him. They had heard the storm of fire that heralded the attack, and seen the great balls of burning hydrogen shoot into the sky beyond the ridges, and they knew that for a little while the torment of the guns would ease, and they cheered the returning pilots, shouting themselves hoarse.