His muscles are shivering because of the position he is crouched in, exhaustion slowly making them stiff, but Sherlock ... has been insistent that he doesn't move, doesn't draw attention to himself.

He can hear Sherlock's voice, his tone cocky, but it is impossible to make out individual words over the distance.

Suddenly, Sherlock's body whips backwards, and John throws any caution into the wind, uncoiling in a split-second and running towards Sherlock before his mind even has time to register what has happened.

...
Exactly three sentences? sorry, this is my first fill ... :)