They landed amid unseen men in the cockpit, and as he scrambled to his feet the inspector cried, "Follow that boat that just went down-river. But no shooting!"
With thunderous drumfire from its exhausts, the cutter jerked forward so rapidly that it almost threw them from their feet again. It shot out onto the bosom of the dark river that flowed like a black sea between the banks of scattered lights that were London.
The moving lights of yachts and barges coming up-river could be seen gliding in that darkness. The captain of the cutter barked an order and one of his three men, the one crouched at the searchlight, switched its powerful beam out over the waters ahead.
In a moment it picked up a distant gray spot racing eastward on the black river, leaving a white trail of foam.
"There she is!" bawled the man at the searchlight. "She's running without lights!"
"Keep her in the searchlight," ordered the captain. "Sound our siren, and give the cutter her head."
Swaying, rocking, the cutter roared on through the darkness on the trail of that distant fleeing speck. As they raced down Blackwall Reach, the distance between the two craft had already begun to lessen.
"We're overtaking him!" cried Campbell, clutching a stanchion and peering ahead against the rush of wind and spray. "He must be making for whatever spot it is in England that is the center of the Brotherhood of the Door—but he'll never reach it."
"He said that within a few hours Ruth would go with the others through the Door!" cried Ennis, clinging beside him. "Campbell, we mustn't let them get away now!"