Run the Firehole 718 through the tungsten bead and the radiant purple bug band, then slide the tungsten tear drop body on. Drop thin UV resin into the tear drop's slot to fill it, turn the slot to the bottom, and cure it in place so the weight is fixed and forms the underbody taper for you.
Start the UTC 70 thread right behind the tear drop body with locking wraps.
Strip two brown goose biots, clip the ends and marry them in reverse so the bevels face outward and the tips align, then measure a stubby tail half to three quarters of the shank. Take a couple of loose wraps to set them, pull down tight, and work the wraps back down onto the bend, splitting the biots with a finger as you go to give the fly a curved, elongated profile.
Trim the biot butts and use them to transition up onto the tear drop body, capturing everything and building a slow taper up its back; without that taper the dubbing slides straight back off.
Spin a noodle of purple Ice Dub and wrap a bulky tapered body forward over the tear drop, stopping just short of the bug band with room left to tie in hackle.
Size a black cape feather against the hook and tie it in by the tip on the side of the shank, then clip the excess tip and any stray fibers so you have an even base to wrap against.
Palmer the hackle forward three or four turns, working it as a soft hackle: pull the barbs outward first, then tease them in reverse and pinch them as you wrap so they lay back into a collar. A half hitch holds it while you work.
Capture the hackle with the thread, cut out any strays, and take a couple of wraps back on top of the collar to sweep the fibers rearward and leave room for the wing buds.
Tie in two white goose biots individually for the wing buds, one to each side, measured against the length of the body and cocked outward. Take one loose wrap to check they match, adjust the length, then wrap firmly, with a couple on top, pull the butts rearward and sneak a couple of wraps in front to flare them up and out of the way.
Clip the biot butts close, come over the top and finish with a whip finish behind the bug band.