Our hapless friend –let us call her Alice – has a prisoner – Bob – and a problem.
Here's the situation: for reasons that are too long to detail here, she must bring the prisoner to a distant location. Using the means of transit currently available to her, that will take at least 12 days. Given that's she's a black belt champion in martial arts and talented in many ways, while her prisoner is bound and not quite so talented, that would normally be a straightforward, even boring task.
As Alice's infamous luck would have it however, the prisoner --Bob-- is capable of entering people's dreams when both he and the victim are asleep. Under normal circumstances, Bob can fall asleep on command. While in the dreamworld, he has enormous power over his victims. It's unclear how vast the powers are, but they can certainly induce a state of confusion that lasts for days, a coma-like long-lasting stupor and maybe even death.
Needless to say, Alice would prefer not to be subjected to any of the aforementioned effects. While the effect seems to be tied to REM sleep, Alice believes that even a 2 minute nap or perhaps even a particularly vivid daydream could put her in grave peril. It is unclear what the physical range of the effect is. While Bob claims that he can enter the dreams of anyone he's ever met, Alice has reasons to doubt that. Alice's current best potential solution will be to tie him to a tree and walk a long way off and take the chance and sleep. This still leaves her with a lingering sense of unease, and she has asked us to try to come up with a solution.
She's already been on the road for 2 days without sleep, so a solution is needed FAST.
How does one travel for 12 days with a prisoner, when your prisoner can probably kill you in your sleep - IF you fall asleep?
EDIT: Alice can be assumed to be generally nice, and it would rather defeat the purpose of her latest adventure if her prisoner stood likely to die on the way back.