This can be managed. This can be survived. This is just like anything else he's been asked to do in the service of King and country--just like any other horrifying thing he had been ordered to do by this crisp firm voice.

"Aye aye, sir."

Maybe, without music, Horatio will be able to focus on finding his way through the movement. Maybe, with the strange tightness in his chest, his sheer will to please this man might drag him along into progress.

Grim determination is the right expression for a dance partner, right?