Just one lock away.
Temperance stalked around the threshold of her foster parent's door, peering at a closed cabinet sharp enough to poke holes in the flimsy wood. She considered herself pretty smart for a young girl, and understood the point of this prisoner's experiment, even if she hated that it had to come at the cost of her toys' freedom specifically.
What does it even mean to play "too aggressively" with toys in the first place? They didn't understand the context!!
And it seems they didn't care to learn, as their reaction of choice was simply taking the 'problem' away from her. Both of her relatively new guardians were very busy people, with very busy jobs, but there probably wasn't enough time in the world to figure out how to both break and replace a padlock without them noticing. So the next best thing came to mind: simply learn to pick it. How hard could it really be? Spies and rogues in stories she heard or games her classmates played could break open a lock in moments...
...Obviously brute forcing it didn't do anything. So the next obvious step: find a different way to learn. It took a full afternoon at the public library to find something about how lockpicking works. It isn't her fault that she actually uses the library card her guardians gave her. With a chunk taken out of her meager allowance to buy a practice lock and a few days of hyper-focus, she managed to finally snap the cheap lock off to regain what was rightfully her's.
And she definitely didn't almost get caught putting it back right when said foster parents got back home that night. Definitely not.
~
Despite venturing into a career path very juxtaposed from previous "criminal intent" (if you can even call it that), there was something about that moment that felt...gripping. If a kid could figure out how to crack a lock in a few afternoons, how easy would it be for people to actually break through most physical security? So she did some testing...which turned into a bit of a fascination. It was less about her trying to figure out how best to pick "the most secure" locks, but moreso a curiosity about how one even built something unbreakable in the first place. There was something so satisfying about seeing every intricate piece of the puzzle come together as the key tilts the chamber into place, to pick something apart and view it from the inside-out. She didn't consider herself much of an engineer...more just a problem-solver. The only person she could trust to keep herself safe was...well, herself. So if she didn't know how these things worked, how could she really be sure of their potency?
Besides, everyone forgets their keys at least once in their life, right?
~
Security is an action, not a state of being. To be safe is to be taking constant steps towards regulation, to stay in motion.
Whatever kind of locks found on these train cars could probably just be kicked in, and if there is truly a monster out there waiting to appear as some deeper and darker remnant of her mind, she needed to take every action she could to keeping things reliable. The compass cabin could regularly expect some kind of unreliable but appreciated barricade in front of the main window to the outside.
And if the locks can't truly keep those monsters out, then if there is ever an obstacle in her way...who says these puny things can keep her out?