'Run!' was all that was said.
Together they scurried down the bridge and halted breathless to crouch by the abutment of the causeway. Then came a dull explosion, a tremor of the earth under their feet, and a cloud of smoke.
'Let's come and see,' said Bracegirdle.
They retraced their steps towards where the bridge was still shrouded in smoke and dust.
'Only partly—' began Bracegirdle as they neared the scene and the dust cleared away.
And at that moment there was a second explosion which made them stagger as they stood. A lump of the roadbed hit the parapet beside them and burst like a shell, spattering them with fragments. There was a rumble and a clatter as the arch subsided into the river.
'That must have been the second keg going off,' said Bracegirdle, wiping his face. 'We should have remembered the fuses were likely to be of different lengths. Two promising careers might have ended suddenly if we had been any nearer.'
'At any rate, the bridge is gone,' said Hornblower.
'All's well that ends well,' said Bracegirdle.
Seventy pounds of gunpowder had done their work. The bridge was cut clear across, leaving a ragged gap several feet wide, beyond which the roadway reached out towards the gap from the farther pier as a witness to the toughness of the mortar. Beneath their feet as they peered over they could see the river bed almost choked with lumps of stone.