Someone tripped across his legs. It was Stirling emerging from the conning-tower. He recognized the sub's very forcible language.

"Hold on," cautioned Denbigh, "or you'll be overboard. The bridge has gone to blazes."

As he spoke the Crustacean shuddered. Her bows rose slightly. With her hull still quivering under the pulsations of her engines she had run aground on a mud-bank on the port-hand side of the river.

Treading warily Stirling groped till he found the engine-room telegraph. Guessing the position of the lever he ordered "Stop". In the pitch-dark engine-room, for every electric lamp in the ship had been shattered, the artificers, facing death amidst the whirring machinery, succeeded in carrying out his orders.

Through the darkness came muttered exclamations and partly stifled groans. Down-stream the Paradox's siren, for want of better means of communication, was wailing in long and short blasts.

"I have brought up to starboard," was the message. "You may feel your way past me."

"There's no may about it," thought Stirling grimly; then, leaning on the twisted bridge rails, he shouted in stentorian tones: "The hands will fall in on the port side of superstructure facing outboard. Bugler!"

"Sir!" replied a boyish voice through the impenetrable gloom—a voice without a tremor save of excitement.

"Sound the 'Still'."

A silence brooded over the stricken monitor. Even the wounded forbore to groan. Then someone appeared from the superstructure bearing a couple of "battle lanterns". Lights, too, began to glimmer through the hatchways, while with admirable promptness the electrical staff set to work to renew the carbons of the searchlights and to test the circuits of the internal lighting system.