11 miles @ 10+ min/mi

Another comfortable night run around my usual Bethesda loop (GB/NIH/RCT), with temps ~40F and little wind. I jog bare-legged, but wear double layers of shorts, shirts, and gloves, with white garments on the outside to maximize visibility

After ~15 minutes bright glowing yin-yang-shaped afterimages develop to block much of my field of view for the next half hour as they grow and spread; are they OcularMigraines? Fortunately the route is familiar, the terrain is fairly flat, and my headlamp is strong. Although I miss one of the mile markers, after I jog through a foggy tunnel for half an hour the aura fades, leaving no apparent ill effects.

Average pace for the first four miles is ~10:55, but I get energized when I reach Rock Creek and blast out miles 8 & 9 in the sub-9:40 zone. I carry a bottle of Gatorade and sip it along the way, in anticipation of inoperative fountains.

About mile 9 I hear a crunching noise in the brush to my right. When I turn my head to look, a pair of bright green eyes stares back at me: a big deer about 10 feet off the trail, coming up from the stream to feed in the meadow. Shortly thereafter I spy two more pairs of green retroreflecting dots, lower and closer-set. It's probably her fawns ...