The swimmer who never missed a day, until she did

I'm at the pool during off-season, the water is perfectly still. I see her in lane three, doing that slow, methodical freestyle she always did—90 minutes, no breaks. I blink, and the lane is empty, but the water is still rippling. I check the clock, and it's showing a date from three months ago. I think I've been dreaming about her every night since she stopped coming. The pool remembers her rhythm better than I do.