In the Mouth of the Whale, by Paul McAuley
Set in the future of The Quiet War/Gardens of the Sun (either ~1500 years or 3.5 teraseconds, depending on who's telling it; but as there's a factor of 100 difference between those, who can tell?). And, yeah. Three interleaved tours of the balloon factory and a literal dea ex machina ending.
Blue Remembered Earth by Alastair Reynolds
This one justifies its tour of the balloon factory as a scavenger hunt around the Solar System, intermixed with elephants. And the following volumes in the sequence seem likely to be taking the scavenger hunt further afield yet, though I shan't be in any hurry to follow.
EmbassyTown by China Miéville
This one actually has an interesting idea about language and communication, though it takes its sweet time getting there, with a lot of scene setting that skirts around the really significant features of the eponymous enclave before actually setting up the salient parts of the status quo and its disruption. Easily, however, the best of the bunch.