There is a–caveat. [ Because it isn't foolproof. Something he found out fairly early and had to rely on other methods. A familiar paranoia slithers up his spine, draping itself over him with the heaviness of velvet: what if he isn't in reality? What if this is limbo and he's just convinced himself that he's in the real world? What if waking up from this nightmare is as easy as putting a gun to his temple and pulling the trigger, like he's done in dreams hundreds of times?

Would he wake up or would he be following Mal ten stories down, thinking he needed to get back to his life?

The precise click and whir of his thoughts stumble, gears grinding against a screw in the spokes. Releasing a noisy breath, the well-oiled rotations begin again, the stopper disappearing between steel teeth. ] Sleep can influence small pockets of dreaming to appear, so the totem isn't always accurate. Typically, they're not too large, though, and they pass with some time.

[ At least, that's been his experience. ]

It's not as dependable if you don't train for it, but in those moments, the best way to tell the difference is to trace your steps back to how you got there.