Whither was the "Albatross" bound? Was she going more than round the
world as Robur had said? Even if she were, the voyage must end
somewhere. That Robur spent his life in the air on board the aeronef
and never came to the ground was impossible. How could he make up his
stock of provisions and the materials required for working his
machines? He must have some retreat, some harbor of refuge--in some
unknown and inaccessible spot where the "Albatross" could revictual.
That he had broken off all connections with the inhabitants of the
land might be true, but with every point on the surface of the earth,
certainly not.

That being the case, where was this point? How had the engineer come
to choose it? Was he expected by a little colony of which he was the
chief? Could he there find a new crew?

What means had he that he should be able to build so costly a vessel
as the "Albatross" and keep her building secret? It is true his
living was not expensive. But, finally, who was this Robur? Where did
he come from? What had been his history? Here were riddles impossible
to solve; and Robur was not the man to assist willingly in their
solution.

It is not to be wondered at that these insoluble problems drove the
colleagues almost to frenzy. To find themselves whipped off into the
unknown without knowing what the end might be doubting even if the
adventure would end, sentenced to perpetual aviation, was this not
enough to drive the President and secretary of the Weldon Institute
to extremities?

Meanwhile the "Albatross" drove along above the Atlantic, and in the