I like the idea. If you can give me a time period and location, I'll join. Somewhere between a kingdom in a medieval era and modern day. It would depend on whether the curse was spiritual (which would result in some potion recipes, I suspect) or modern-day experimental (an organization is testing the effectiveness of a pathogen). Hm.

Let me try the second. A modern-day organization with nasty intentions is experimenting with neurological and biological warfare. They isolate a virus that is potentially incurable. Unfortunately, the effects will take at least two weeks to kill a human. To see if the risk is worth the payoff, they select two random individuals from a semi-rural area, abduct them, inject them and drop them off in an unknown location under control of the organization. They select a male and a female to see if the effects are identical for both genders. As soon as they wake up, the clock starts. If the virus acts in the way they predict it does (I assume the effects are mostly internal and simply slow a person until they die, although we can mess with it as we go), they will use it for...whatever. 

Since this is an area under the organization's control, the people there know that anything abnormal was most likely instigated by them, so seeing two random people with strange markings would imply that they are unwilling test subjects, and no one wants to talk to someone like that because they might be contagious. 

If possible, we should gain access to someone who knows about the program, or is a defector, or escaped from their facility, or was following us to see how the effects affected our lives (who we can catch and interrogate if necessary). It's not going to work well if we need to get from A to B with no idea what or where B is after a week.
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Is that enough of a foundation? I've left out some important stuff (the name of the org, where they are, what we need to do, etc), but it's a two-person story, so I'll wait for your input.