This light was not stationary. It crept down through the inky sea toward the fugitives and grew larger and brighter in their eyes.

“W'ot is that?” cried several apprehensive voices.

Caradoc stood erect by the rail, watching this new development.

“Malone,” he called to the man hidden on the bridge, “what speed can this boat make?”

“Hi've got as 'igh as eighteen knots out of 'er, sir.”

“Signal 'full speed ahead' and call down to the firemen for all the steam we can carry.”

“Very well, sir.”

Caradoc looked at the light for a minute or two longer and then remarked to Madden.

“They couldn't have repaired that submarine for several hours longer. They must have had two.”