Spoiler
Does Xandra know anything about this Azure Lich? Knowledge (Arcana): [roll]d20+6
If Xandra knows who the Azure Lich is, then:
Xandra crosses her arms behind her back and raises her eyebrow. Tainted riverways are the least of your concerns if the Azure Lich is in control of these waters. If you feel this vessel is under-defended, then my companion and myself will gladly lend our skills. For a price.
If Xandra does not know who the Azure Lich is, then she'll stand silently with an unconcerned look on her face, even though she's rather excited about the fact that she may have the opportunity to study tainted samples of water, and what powers they could add to her alchemical skills.