dude you just took a left turn onto a one way street into heavy on-coming traffic by giving mulder the sword...

Good idea, but it needs a bit of improvement. First your punctuation needs work. A lot of your dialogue is missing periods, giving the whole story a rushed, slurred feel. You've got way too many commas. Put them where the dialogue pauses, not where you breathe. Also, work on capitalization. Proper grammar and punctuation can improve clarity, control pacing, generally make the story look more professional and clean.

Next, put two spaces after a period. Also, (Don't worry, I had the same problem.) Second, the story lacks description. Yes, the construct fast and has teeth and claws. But what beyond that? Does it have scales? Horns? Fur? Or is it a monstrosity made of only teeth and claws? Don't just state things, add adjectives and detail. What about the crime scenes suggests that the perpetrator is trying to make it scream "A vampire did this?" The utter lack of drama and detail given to the scene where Mulder picks up the sword borders on crimminal.

Third, the story is disjointed and rushed. You do a big infodump in the introduction, then drop us into the middle of a fight scene, which ends anti-climatically and zips into Mulder spouting off magic technobabble with no explanation of how he learned it...It just goes to fast, and too confusing. The whole story seems like a dream where everything is vague and fleeting. (The elephants in the mirror scene doesn't really help either, it's distracting.)

A better idea would be to start at the first death and bring in Mulder and Scully then. From there, you could of slowly leaked all the information in the intro over several chapters as you built up the tension. Also, there was no need to give Mulder a Book o' Magic; he's very knowledgeable about the occult in any case, and it's entirely plausible that he knows what a construct is. If you wanted to, you could have made the book a plot point (loading it with really obscure/forbidden knowledge).

*Stretch* Now let's see what you did right.

The intro is definitely written in Dresden style. It could have been taken straight out of one of the books.

Second, the premise was clever. A vampire killing Dresden so to gain a shot at becoming vamp king is a good idea, and the whole "Manipulate Dresden into the open by killing people" concept is workable.

Third, giving Mulder the Sword of Faith is a neat idea. It fits him very well themeatically (the whole "I want to believe" thing) and puts Mulder and Scully into the zone where they could go up against the high-powered Dresden-verse villians. You could of just made the whole delivery so much more awesome...

End Verdict: Good ideas, poor execution. You could have done so much more with this...

An intreguing beginning. Will look forward to seeing where you go with it.

Really interesting start! Definitely looking forward to more. Haven't seen this crossover before ^_^