Scully's getting stalked, and when she disappears, Mulder finds their relationship under suspicion, whilst he searches for her. Meanwhile, she's not inclined to just sit back and wait to be rescued.
This is a fic I came across whilst I was searching for another story, and I'm very glad I did. I usually avoid established relationship fics because I like a bit of excitement, IYKWIM, but there's no lack of that with this pair, despite them being together almost 2 years at the time this is set.
There's the angst of Mulder and Scully both being in danger, then more angst when nobody would believe Scully had been kidnapped, thanks to some bruising left by Mulder. 😉 After Mulder is sidelined by the bureau, our agents have to each rely on their wits to get back to each other. A++++