Cloak Games book 5. With spoilers ahead.
For instance, the Knight of Grayhold shows up to make sure she gets a delivery: ways she can get two men to help her with her next task, so he can collect on his favor.
And then Morviland sends her off to Venomhold, also in the Shadowlands, to steal from its knight.
Riordan is willing to help. And both men are honor-bound. She's met them, too.
It involves rubies, a tower that is justly name and that you need protection against, dwarven embassies and hair-splitting, persuading people that something will fulfill their oaths, revelations about Rebels, and more.