Spoz wrote:Potentially - Schueler? If he is some sort of double agent or agent provacteur inside Langhorne's group, as may be suggested by the stone and the ending of TFT (even if that particular apparition is a function of Nahrmahn and Owl) then possibly he is actually in on the whole thing - and may help explain the existence of the stone.
While it is possible Kau-Yung expected Schueller to be there with him, we know from his interactions with Seijin Cody that Schueller was not present when Kau-Yung set off his vest pocket nuke. For that matter, narrowly escaping being caught up in Kau-Yung's nuclear murder-suicide might well have turned Androcles into the sort of person who could author the Book of Schueller, if he actually wrote it.
If Kau-Yung was referring to a double agent within Langhorne's clique, my guess would be the unnamed angel who keeps visiting Lakeview at the start of Off Armageddon Reef, who could have been Schueller though I don't think so. Whoever that unnamed angel is, it would make sense for him to show up, even if only in flashback, when the Safehold series concludes.