Textev from HFQ: "Anyway, the references in the Writ - and in Kohdy's diary - to 'fastnesses in the Mountains of Desolation' suggest the Fallen had been preparing for some time. Once the fighting began, however, any small industrial modules they'd managed to hide away in the mountains were enormously outclassed, because Hamilcar hadn't been disposed of."
Later, in TFT, we have the Charisians supporting the development of the provinces in West Haven - including the Desolation Mountains.
Could the early reference to the use of the Desolation Mountains as a Fallen base of operations in HFQ be a Chekhov's gun? With all the new development going in in West Haven - with Charisian help and funding - might we see the discovery of a heretofore undiscovered Fallen citadel?