It was the work of but a moment to enter the tank, and, after making sure that the machinery was all right, Tom and Ned made their way to the interior. In one of the smallest rooms they found Koku and the others bound with ropes, and in a bad way. Koku was so tied with cords and hemp as to resemble a bale of Manilla cable.
"Cut 'em loose, Ned!" cried Tom, and the bonds were soon severed. Then came explanations.
As has been told, one of the plotters, whose identity was not learned until later, came with the forged note. The giant and Tom's men set out in the tank, and the machine was stopped at a certain place where the plotter, who gave the name of Crossleigh, told them Tom was to meet his men.
Out of ambush leaped Simpson and others, who overpowered the mechanics, even subduing Koku after a fierce fight, and then they took possession of the tank, making the others prisoners.
What happened after that could only be conjectured by Tom's men, for they were shut up in an inner room. It seemed certain, though, that the tank was taken to some secret place and there painted to resemble the verdure. Then she went on again, coming to rest where Tom and Ned saw her.
Meanwhile the plotters were gradually getting at the secrets of construction, and they were in the midst of this work when one of them saw the aeroplane. Rightly guessing what it portended, they left hurriedly, still leaving the hapless men bound, and started the tank on what they thought would be her last trip.
"But you saved her, Tom!" cried Ned. "You saved her with the wireless."
And word was sent back to Shopton by the same means to tell Mr. Swift, Mr. Damon, and the others that Tom and his tank were safe. And then, a little later, when the bound men had recovered the use of their cramped limbs, the tank was backed away from the ledge and started on her homeward way, Tom and Ned preceding her in the Hawk.
Without further incident, save a slight break which was soon repaired, Tank A soon reached her harbor again, and a double guard was posted about the shop.
"And they won't get much more chance to steal her secrets," said Tom that night, when the stories had been told.