The Serendipity comes from Blue Ribbon Flies up out of West Yellowstone and at this moment, has become a pretty old school pattern. A simple midge/caddis pupa, the Serendipity uses just a couple of materials and can be tied slim and sparse or heavy and chunky to better replicate your insect of choice. I’ve used this pattern on our western tailwaters with good success as well as on rivers like the Colorado.
Hook: TMC 2487 #14-22
Thread: Red 8/0 UNI
Body: Red Darlon or Z-Lon, twisted into a cord
Thorax: Natural Deer Hair, cropped short
Start the thread just behind the eye and wrap a thread base down around the bend of the hook taking care to keep it smooth and flat. Return the thread to the starting point.
Tie in about a third of a strand of Darlon or Z-Lon an eye length or so back from the hook eye.
Wrap back over the Darlon to the end of the thread base and return the thread forward again to the starting point. Trim any excess Darlon at the front flush.
Roll the Darlon in your fingertips until it spins into a hard cord. Grab the loose end in a pair of hackle pliers to help maintain the twist and begin wrapping the cord forward up the shank in abutting turns.
Wrap the corded Darlon all the way up to about an eye length back from the hook eye and tie off. Clip the excess. Make a thread base from the tie off point to the hook eye and back again.
Cut and clean a small bunch of deer hair. There is no need to stack the hair as the tips will not be used. Cut the butt ends as squarely as possible and lay them on top of the hook with their ends just behind the hook eye.
Make two wraps of thread over the hair, one on top of the other.
Pull toward you with the thread to flare the hair butts on top of the shank while holding the tips firmly in place. Once the hair is compressed, make an angled turn of thread around the shank to move the thread forward to just behind the eye. Whip finish and clip the thread.
Trim the tips of the hair into a short brush, just slightly longer than the butt ends.