Tom Swift and His Chest of Secrets

THOUGH he had no more than very slight clews on which to pursue the robbers, Tom Swift was not without a definite plan on which he proposed to operate.

As he had mentioned to Ned, he had obtained information which indicated that the big blue aeroplane, after the robbers had put the chest on board and had left Koku tied to the tree, had departed toward the west. Of course there was no guarantee that it would keep on this course, and absolutely no way of telling how long it would hold it.