During the trip to Mexico to which reference has been made, Ned Nestor had succeeded in averting serious complications between the government of that rebellious republic and the government of the United States. Through his efforts a threatened raid across the Rio Grande from the Mexican side had been checked on the very border, and the secret service men associated with him did not hesitate to declare that his tact and activity had done much to prevent a war between the two countries.

Before leaving the scene of their operations in Mexico, Lieutenant Gordon had been ordered to New York on important official business. Only an inkling of what that official business was contained in his letter of instructions. Only the bare fact that complications in the Canal Zone were placing the Panama Canal in danger was conveyed to him. Later, after his arrival in New York, he had learned that the government suspected plots to destroy the great Gatun dam by the use of explosives.

Only a hint of the threatened danger had been conveyed to the War department, but that was enough to set on foot the investigation of which Lieutenant Gordon was to be the head. One of the lieutenant’s first acts after receiving his instructions was to secure the services of Ned Nestor, being guided in this by the wonderful success of the boy’s efforts in Mexico.

Thus it chanced that on this night every boy who had had the good fortune to share in the Mexican adventures was importuning Nestor to use his influence with the lieutenant in order that they might all be taken into the party. They had already gained the consent of their parents, Nestor, individually, was willing, and it only remained to convince Lieutenant Gordon that they could be of use to him and the government on the Canal Zone.

“If you don’t loosen up and take us with you,” Harry Stevens declared, with a grin in the direction of his companions, “we’ll give you a chase to the equator. You know how you found Jimmie in George’s bed? Well, if you don’t take us along with you, you’ll find us all in your bed before you get to Panama.”

“It seems a pity to unload such a mess of wild animals on the people of the Zone,” laughed Nestor, “but we’ll leave it all to Lieutenant Gordon. Lavish your honeyed words and smiles on him!”

“What’s it all about, anyway?” demanded Jimmie. “It’s something concerning the big canal, I know, for I heard you two talking of explosives at the Gatun dam.”

“We all heard that,” cried Jack Bosworth. “You can’t keep secrets from us. What is it all about? Is some one trying to blow up the big dam?”

Nestor looked into the faces of the boys with serious eyes. He had not suspected that they knew anything definite regarding the secret mission, and was annoyed to think that he in part might be to blame for the leak which had been discovered.

“Is that what you’re going for?” asked Harry Stevens. “Are you going to mix with governmental affairs again? Because we’ve got to go if you are. Honest, now, we won’t say a word if you tell us.”