Well, step one, try to write down all the weird-observations he can think of. (In Baseline, but in a trivial cipher that Keltham can sight-read and sight-write. It probably doesn't help much against scrying, with the Conspiracy also reading his mind, but maybe every little bit helps.)
He made a first pass last night, in his head; he didn't write it out, then, in case magic could read codes and Security was peeking at his notes. Mindreading hadn't been as prominent in his hypotheses then.
Turns out, it gets a lot more detailed when he writes it all down.
Maybe he should've done that before his trip-by-scry, even if that would've given the Conspiracy much more time to prepare... no, Keltham is sticking with that first decision; if the Conspiracy was learning and preparing as fast as it looks, a quick early trip was the correct decision. He can, if necessary, ask for another trip later.
Actually, doesn't that further imply that the Conspiracy wasn't reading his mind last night, if they weren't alarmed and alerted then? Did he do something that tipped him off this morning, before he even got to Ione, that didn't tip them off last evening? Add it to the list... actually, the part where he prayed for spells, if they can cheaply read the response from Keltham's god coming back, but mindreading him is more expensive, would be one obvious theory... Say that mindreading requires Lrilatha around here somewhere, hidden, but Maillol, no, Subirachs because she was posted here later and could have special relevant talents, can read it off when Keltham's god grants him alarming-looking spells.
...his teacher did say to not let yourself be distracted during the observation-collation step.
Right. Back to that long list of observations.