Chemical Reaction

Tony Stark and Y/N L/N have never seen eye to eye on anything. Their rivalry went as far back as their time at MIT. The two can't be in a room longer than five minutes before arguments ensue. At Fury's request, they're being forced to work on a project together. In an attempt to identify a component of a weapon the Avengers acquired from a Hydra base and destroy it, the component let out a burst of energy affecting Tony and Y/N. Their DNA had been altered in a way neither of them would have expected. One that created a mark on the inside of their wrists. Time is running out to find a way to reverse the effects of the mark. But what they find is that maybe, the change wasn't as terrible as an experience as they came to believe.