Random thoughts:
Amberley sat in her stateroom, nursing a glass of amasec and considering what he wanted. Not Cain. That was a problem for later and the Hereticus. She was well clear of him. Hopefully. No, Leirahaz was her problem, both in the sense that he'd attacked her and in the sense that as an Aeldari he fell within her jurisdiction.
Understanding a Harelquin's intentions was even more a matter of guesswork and supposition than dealing with any other member of that famously convoluted species. But in her experience, the best way to go about it was to ignore everything they said, most of what they did and just look at the outcome of the situation they'd messed with, assume it was what they'd intended and go from there. So what had been the result of their manipulation?
Well, beginning from the beginning, her investigation into the smuggling operation was thoroughly derailed. The fact that it had been done by a Drukhari raid might mean there was some greater connection to the species as a whole...but she doubted it. The most likely thing would have been either archaeotech they wanted, or soul-stones and in either case, she thought she would have heard it discussed, if only as they butchered each other for the prize. Also, she knew what they'd been smuggling and it was T'au tech. That had been her focus recently, trying to slow the spread of T'au technoheresy and concomitant influence.
The thought brought a flash of Cain's speech about the descent and degradation of the Imperium, was it really enough to try to 'slow' T'au influence? Surely she should be doing more? But maybe that was exactly what the Harlequin intended? No, that way lay madness and endless second-guessing. She shoved the thought aside.
It wasn't the smuggling operation (probably). She'd also been taken out of play and her team (and ship) becalmed for almost a year. But there'd been nothing important they'd been intending to do, merely more of the same sort of operations. Perhaps she'd have stumbled over something, but that could have been resolved by just becalming her ship, or killing her. Of course, that wasn't necessarily controlling when dealing with a Harlequin, who raised baroque plotting to an art form that their Drukhari cousins could only marvel at.
But she doubted it. No, the single major effect, due to her total failure to assassinate Cain was the Panacea. Delivered into her hands, directly, due to Laihez's personal intervention. That was the main outcome of all this pain, terror and stress. And a worthy one, if Cain had been telling the truth about what it was. The greatest threat to Nurgle she had ever heard of. But Aelderi cared little for that monster, focusing their fear on the beast they had birthed. So why would a Harleq-
Isha.
Amberley was no Malleus expert, and was grateful not to be, but the daemons Xenos worshipped were part of what she needed to understand. And Isha was one of the Aelderi's so-called gods. Imprisoned by Nurgle for millenia. Why would a Harlequin help arm enemies of Nurgle? To open the way to their lost goddess. And if Nurgle's wrath fell on the Imperium, or Slawkenburg, or all Mankind? Well, what did an Aelderi care?
She leaned back heavily in her chair and considered it. It wasn't certain, of course. No one but a fool would say for certain they had untangled a Harlequin's web of deceit, but she thought she had it. Arm the Imperium against Nurgle, set the two to fighting (more than they always did) and then, when his gaze and forces were committed to hunting down and destroying the Panacea, sneak in and steal Isha away. Strengthen themselves and weaken their enemies.
That...didn't actually answer any of her questions about what to do next, though. Some part of her wanted to chuck the damn thing out the airlock, just to mess up Leirahaz's plans, whatever they were. She was pretty confident that wasn't what the Aelderi expected. But the rest...it would be a gamble, but if she could spread it far enough, fast enough, then Nurgle would have to destroy the entire Imperium in order to destroy the Panacea and if he could do that, he would have already. Yes, that was the only course open to her. But, of course, that was exactly what Cain had asked her to do. That was a problem. If she did it, he would always have that on her. Surely, he had recorded their conversation, if it leaked to the wrong inquisitors, it would look like she was doing his bidding.
Her eyes closed. Then opened again. Throne damn them all for fools. She would do what was right and if anyone got in her way, well, she was an inquisitor and they'd regret their folly. Briefly.