Carrying full staysail, jib, foresail and mainsail the schooner plunged into the waves, sending cascades of water over her forecastle with every leap. She was loaded deeply and the boys could see that she would prove to be what the sailors term a "wet ship."
Every moment the speed was increasing. The mate had trimmed the sheets to the exact point for greatest efficiency.
Suddenly all hands were startled by a hail from a point on the starboard bow. They saw a small motor boat riding dizzily upon the crest of a wave one moment to be dropped out of sight in the trough the next.
"Ahoy, the launch!" bawled out the mate in a voice of thunder. "What do you want? Stand off or we'll run you down!"
"We want those passengers of yours!" was the reply.
"All right, come on and get 'em!" yelled the mate above the noise of singing wind in the rigging. "We can't stop now!"
"If you don't heave to I'll fire!" was the answer.
"Good night!" cried Jimmie from a position near the lee rail, where he could look out beneath the main boom. "That's Mackinder!"
A revolver shot sounded amidst the tumult of rushing waters and singing rigging. The echo was quickly bitten off by the rising wind. The shot sounded dully above the humming and roaring.
Before Ned could detain him Jimmie fired. Faintly the boys heard a crash aboard the motor boat. The green starboard sidelight of the launch disappeared. Urged on by the tremendous press of wind in her sails the Lena Knobloch was fast dropping the launch astern.
No other shots were fired at the schooner. Scrambling from his position at the starboard rail Jimmie made his way aft to a point beside the helmsman. Here he peered eagerly into the darkness astern.
"I can't see them at all!" he announced, turning presently to his companions, who were grouped about the little skylight.
"Perhaps we've shaken them off for keeps!" ventured Jack. "Did you see who that was with Mackinder?"
"I thought," said Harry, "that it was his pal, Norton!"
"Well, they're safely out of reach now!" declared Ned. "I'm glad of it, too! If we can hold on at this gait we'll soon reach a port in England, where we can transship the Grey Eagle and get home."
"I only hope the real 'U-13' doesn't come along and demand that package from us!" laughed Harry. "They might take a notion to send us to the bottom if we don't deliver it on demand!"