Context
I am working on a game and one of the Classes in it is "Rogue". (Original, I know.) I'm trying to find a term that accurately describes and can serve as a name for one of the Subclasses. (Preferably a single-word term, if possible.)
Needs
The term ideally needs to describe somebody who excels at 1) following a target, 2) breaking into locations, and 3) collecting information without being caught. It should ideally be able to work as an adjective if at all possible, but an attributive noun could work (with some leniency for other nouns, but if possible, please avoid as such), potentially; however, the term should not imply an occupational aspect to the behaviour (such as "Spy" or "Investigator"). It shouldn't be inherently a very negative term either, as is the case with "stalker" or "prowler". It shouldn't imply theft such as with "thief", "burglar", or "robber". I'd prefer one word, but a two-word option could work as well, but please, nothing larger than that.
My Effort
Due to personal reasons, my first thought was "Stalker", but that word conveys too heavy of a connotation. My second thought was "Lurker", but it had a similar issue, alongside the fact it doesn't imply most of the conditions. I tried "Trespasser" but that feels too heavy on the Breaking & Entering side with little implication of following a target. "Scout" doesn't work because it is too generalized (ignoring occupational implications, of course).
Conclusion
I know I am asking for a tough answer. If you can help me, I'd appreciate it. I'm still trying on my own to find a good word, but if anyone can suggest something that helps, I'd be so grateful! I know this comes across as super picky, but I tried to be specific so not to waste anyone's time. Please and thank you!