A drop-dead gorgeous mute is bartered into a harem where beauty is a death sentence and she must find her voice to survive.

It sounds as if the antagonist would be one of the other women in the harem, therefore, the antagonist needs to be described and the dangers clarified. Will the antagonist try to kill her? Administer genital mutilation on her? Threaten the her family?

"...find her voice..." reads as a weak action for a logline, is there anything else she has to do in order to survive? Does she need to climb the ranks of the harem in order to survive? Kill or be killed?

>>>> where self-expression prompts life-saving action.

Which action is....?

What is her objective goal given her circumstances? ? How does "self-expression" translate into a specific action plan to rescue herself (if no one else will ) from her predicament?

"Beauty a liability" as in 283 jealous females who want their competition dead ... "mute finding her voice" as in a character arc where self-expression prompts life-saving action.