Upon arriving in Kristiania, Passepartout and Fogg notice that it is completely deserted. There are no signs of a battle or unrest. There is a comfortable hotel to stay in, but it is also completely abandoned.
Only after exploring do the pair uncover the truth; the people of Kristiania have relocated the entire city underground. Many Kristianians believe that Europe will soon descend into all-out war and shelling from airships will make subterranean accommodation the safest. They have set up a thriving market as well as developing a method of farming crops using phosphorescent seaweed.
After locating the real Kristiania, Passepartout and Fogg are able to stay in an underground hotel. There they can meet fellow explorer Otto Lidenbrock. Lidenbrock can easily be met by arriving via Amsterdam. Those travelling from Cambridge must wait before leaving, so that they arrive in time to first explore the city, and only then to sleep in the hotel.