If it was stored flat, you might be lucky. If it was stored standing on it's end, I about guarantee you got a twisted limb.

Do NOT pull on that string or attempt to shoot it with that string. It's dacron, probably B-35, and that stuff wasn't meant to last 18 years on a bow. It could very well break at full draw or with the first arrow or two. Carefully unstring it, check the limbs for any twist, and if all looks good get another string (dacron only--B-50 or B-500).

If you have a mild twist, most likely it can be straightened. Good luck!

Chad