An August evening. It means a possibility of caddis hatch where you live. They are rhyacophila, one of the two caddis species you know by name. They hatch after sunset. Last time you were here it didn’t happen.
There was some good fishing soon after 6 pm. when you arrived, but then it has been quiet. You take a break, eat your egg-bacon-sandwich.
Start again, fish a small streamer with soft hackle dropper. You start catching small trout. Replace the streamer with a size 16 caddis pupa. It’s getting dark, and the trout are everywhere. The best fly is a dry fly, green bodied Deer Hair Sedge.
When it is too dark to see your fly, you switch back to pupa pattern and feel the trout taking it. And when they stop, you stop.
You lived again.