This fly is a gumbo of not necessarily related ideas--make a relatively simple maximum twinkle nymph with a bead buried and at least partially hidden in the thorax area rather than its normal high profile position up front.
A tuft of marabou fibers gets twisted in front of the bead. A shiny forward-facing plastic wing case installed before the marabou tuft then gets pulled back and whip finished behind the thorax instead of in front. Crystal flash ribbing for even a bit more twinkle.
#18 hopper hook and bead
duck flank tails wrapped all the way to eye to help fix the bead position as a first step
dubbed abdomen ribbed with Crystal Flash
Lateral Line material for the wing case
marabou tuft for the legs
On a slightly off-color Yellowstone float last week we tried just about every wet fly in the book including various Partridge soft hackles and even a few Bird's Nest Nymphs. Dry flies weren't happening and neither were streamers. Among all the flies we tried the best were Willy Self's hot hot hot pink Laser Midge and the brightly high contrast Prince Nymph. Twinkle is as twinkle does. I'm a believer.