Slide the Firehole Tungsten 2.5mm Copper bead onto the Tiemco TMC 2499 SP BL and start the UTC Red 70 thread behind it. Keep the thread flat throughout; a slender profile is the point of this fly.
Colour a short length of the hanging red thread black with the Sharpie. This blackened section becomes the rib.
Wrap a slim red thread body down into the bend. If the black section arrives before you reach the bend, add a few extra red wraps at the rear so the black starts there.
Advance the blackened thread forward in open turns as a rib over the red body, then take a few wraps behind the bead to hold it in place.
Coat the body with black UV resin, spreading it thin and even over all the thread with no bulk anywhere, then cure it with the torch.
Build a few thread wraps right behind the bead as a base for the thorax.
Tie in a length of Waspi Mirage Tinsel - Medium on each side of the shank as cheeks, roughly even.
Dub a thorax of SLF Spikey Squirrel - Natural Fox behind the bead.
Pull one cheek forward down the side of the fly and bind it, then the other on the opposite side, keeping them about even. Take a securing wrap and trim the excess tinsel.
Whip finish behind the bead, leaving a small red thread collar.