Sherlock Holmes heard the muffled grunt from beside him. He looked over in time to see Watson wrench his boot out of a hole in the dirt, his foot twisted in a way that seemed unnatural. They were running, however, and there was no time to slow down to help. Holmes expected Watson to fall behind, but in only a few moments his friend was back by his side.
Together they tackled the criminal they were after, Holmes taking pains to pass him off to a constable as soon as possible.
He took Watson by the arm afterwards, steering him towards home.
"How does your ankle fare?" he asked.
"Hurts like hell," Watson answered stoically. "I didn't think you'd noticed."
"I make it…"
"Your job to notice things. Yes, I know, but I suppose I simply didn't realize you have eyes in the back of your head."
"I wouldn't have, you know, if I hadn't seen it happen," Holmes commented.
"Oh?"
"No. You're always a stalwart companion, Watson, but I suppose I didn't fully realize what metal you're made of. Here: we're home. Allow me to help you get your boot off; your ankle will undoubtedly be swollen. There! That's better. Rest with it up, now, I will fetch our pipes, and we will see how lazy this afternoon can become."
For the prompt from goodpenmanship: twisted ankle.