‘Go!’ screamed Brimstone at the coachman.
The man whipped the horses at once and the coach sprang forward, hurling Chalkhill backwards to fall heavily on a none-too-well-padded seat. ‘Squeak!’ he gasped.
‘Guard!’ shouted the Customs Officer. ‘Halt that coach!’
Armed men began to pour in a steady stream from the Customs Houses. Brimstone leaned out of the coach window and tossed a multi-coloured ball towards them. As it struck the ground, it began to belch a rolling, rainbow smoke.
‘Look out!’ called one of the men. ‘It’s a screamer!’
On cue, the ball emitted a blood-curdling shriek. Chalkhill clapped his hands over his ears. The running guards split into two streams like a river striking a stone. The screamer bounced between them, gathered speed and hurtled towards the open door of the Customs House building. As the smoke rolled over the men, they too began to howl. Several of them broke ranks, dropped their weapons and ran off in sudden panic.
Brimstone struggled to close the window of the coach as it hurtled towards the archway. Behind him, the jolting motion disturbed the nants again and they set up a discordant wail that echoed the screamer.
The screamer itself clicked loudly and metamorphosed into a score or more of smaller, multi-coloured spheres, which bounced, scattered and finally flew with unerring aim towards the windows of the Customs House.
‘Evacuate!’ someone shouted.
Each of the smaller spheres was shrieking now, filling the air with a manic howling that scrambled thought and chilled the blood. The horses leaped forward as if stung, then thundered through the archway en route for the tunnel. Brimstone had the window closed now so that the noise outside was muted to a bearable level. All the same, Chalkhill could hear the sound of shattered glass as spheres crashed through windows.
All went black as the coach plunged into the tunnel. From behind came the clump-clump of regular explosions. Then the coach emerged into the sunlight. Chalkhill dragged himself to his feet and opened the window again. He leaned out and craned to see behind. The massive structures of the Customs Houses were collapsing one after another in a pall of rising dust and smoke. The shriek of the screamer was replaced by a wailing siren. Flames leaped towards the sky as billows of black smoke rolled across the ground. Men were running everywhere, their faces grey with panic.
The coach picked up speed as it drew away from the scene of destruction.
‘That went well,’ Brimstone remarked.
Chalkhill said nothing. All he could think of was that he hadn’t managed to stop payment on his bank draft.