A retired cavalry soldier is forced to partner with a Cheyenne Indian to track down a serial killer who has kidnaped his daughter.

Btw that is why I dropped 'forced' from my logline example lol. Great Comment!

If you must use a must in your logline, then you must have an or else, or else the must won't have meaning or stakes.

The lead character Must do this Or else this bad thing will happen.

A logline guru on this site once stated:
If you have two opposites who must team up together, you must (In the logline) give us the compelling complication which leads to their unlikely alliance. Likely this will be the hook of your logline so don’t leave it out. Your logline will greatly improve by adding it.