The Chemickal Marriage

of a jump.’
    ‘
Ah
. Perhaps –’
    Chang slashed his hand through the air to indicate silence. They followed his gaze to the hatch, which Phelps had not replaced, and the flickers of light that danced in the tunnel beneath.
    Chang waved them brusquely to the cistern of water, where Miss Temple told the other two men which valves to close. The squeaking valves were heard in the tunnel: lantern beams stabbed into the chamber. Chang crossedto a smaller cistern, wrenched at the spigot head and leapt clear of a spew of green liquid. The chamber floor was angled exactly for this purpose, and the steaming chemicals gushed straight at the hatch. Chang ran for the ladder. Phelps was in the lead, then Miss Temple, and finally Svenson, climbing with the speed of a tortoise.
    Shouts of outrage echoed from the tunnel, then the crack of lantern glass bursting from contact with the liquid. Chang shoved the Doctor’s rump without ceremony. A hand rose through the sick green flow and then a gasping, shaking head – one of the Xonck soldiers, more intrepid than the rest. Chang looked up to see Phelps’s feet disappearing into a pipe above the cistern pit, Miss Temple right behind, balanced on the slippery rim. Svenson reached the top of the ladder but quailed at the four-foot gap to the pipe.
    The soldier hauled himself clear and saw them, his shaven head gleaming green. He aimed a pistol at Chang’s back, but the hammer clicked impotently – the chemical wash had done something to the charge. He tried again – more heads rising to the hatch rim – then threw the gun aside and drew a wicked knife. Miss Temple had entered the pipe, but Svenson stood fixed.
    ‘It is just like the gangplank of a ship!’ cried Chang.
    ‘I despise gangplanks!’ But the Doctor lunged forward. Three reckless storklike steps and he was there, Miss Temple catching his arm.
    Chang readied one of Foison’s knives. The bald soldier had reached the ladder. Chang considered throwing the knife, but he’d not Foison’s skill. Another two men stood at the hatch, pistols snapping without effect. Chang ignored them, waiting for the bald soldier – climbing with one arm, the long knife held upwards. The green liquid had bleached his uniform yellow, and his coat seams split at the effort of his arms. Chang feinted a cut at the climbing man’s face, which was aggressively parried – but all Chang sought was blade contact. He deftly turned his wrist so the silver tip of Foison’s knife drew a sharp line along the soldier’s hand, cutting deep. The long knife leapt from the man’s grip. Chang snapped a fist into the soldier’s nose, the man’s feet went out from under him, and he slid down the rungs. Chang crossed the cistern rim as quick as a cat and was gone.
    Like fools, the others were waiting in the pipe. He shouted them on, but then caught Svenson’s foot and called for a pistol. He could not count on all their pursuers’ firearms being disabled. Svenson passed back his revolver. Chang crawled furiously, then turned and aimed for the diminishing circle of light at his heels. He squeezed off four roaring shots and slithered on – the pipe was coated with slime – then turned and fired two more.
    The pipe angled abruptly down and Chang slid out of direct range with relief, and just in time, for the metal behind him echoed with gunfire. He pressed himself flat, but the ringing ricochets spent themselves at the turn. He kept crawling. The pipe changed its construction – intrusive ridges where each individual piece had been riveted together. Chang clipped his knees and elbows groping forward.
    More shots came from the cistern, but nothing found its mark. Chang feared the other end of their journey. Surely Foison’s men knew where the pipes led, and might run over land more quickly than they could crawl like worms. Abruptly Chang’s face met the grimy sole of Doctor Svenson’s boot. He swore aloud, spitting, and the Doctor’s whisper reached him. ‘Do you hear it?’
    ‘Hear what?’
    ‘The
water
.’
    Chang listened. Of course … far more effective than any scramble of men, Foison would simply reverse the valves. He wondered how it had taken them this long to think of it. Chang slapped Svenson’s foot.
    ‘Go on, as quickly as you can – we cannot go back!’
    ‘We will drown!’
    ‘And if we go back they will shoot us! For all we know we are near the finish!’
    They scuttled like crabs before a looming wave. Chang heard