I knew by the third block

I knew by the third block.

The heel going soft and then raw,

the particular heat of skin

deciding it has had enough.

I kept going anyway—

six more blocks, then eight—

because I had underestimated the distance

and I wasn't going to say so,

not even to myself.

Not until I was sitting on her stoop

with my shoe off,

looking at the bubble—

the way the fluid sat there

perfectly clear, the skin gone white

at the edges like a warning

that had already passed.

I knew this was happening.

That's the thing.

I pressed my thumb against it once,

to feel the give,

then put my shoe back on.