Hunting Shadows

Audrey Slater is one of the Union's top bounty hunters. She works alone, she only takes red file assignments, and she has a perfect reputation.
So does Audrey's new partner, Sydney. Sydney is cold, angry, and not happy to be working with someone. Too bad the decision wasn't either of their choices; it came straight from the Union's board.
The assignment itself? Find a rogue group of criminals operating across the worlds. They keep a low profile, low enough that the Union had to assign their two best members to work the job. The whole thing is a secret- Audrey and Sydney are supposed to solve this quietly and without any fuss.
The run-along that lives outside of Sydney's house is definitely stalking Audrey and the ongoing assignment. He turns up in other worlds where the pair are trying to find their targets. He might be able to help, though.
The further into the assignment Audrey dives, the more unsure she is. What exactly did this group do to bring down the Union's wrath? Why did they swear that the Union is lying? Why aren't there any reports on the group? Why is the assignment so much harder than it was supposed to be?