Give a strong, active sentence or two that sums up the final confrontation. Resolve whatever remaining conflicts are keeping the hero and heroine apart. Does it give the HOW and WHY of your story, as well as the what. Rewriting and rewriting and rewriting again is essential to a putting together a selling synopsis. Once you're convinced yours makes both logical and emotional sense, take some time with your technique.
Simple sentences are especially effective for emphasis and in action.
Check for this. It keeps your narrative vital. Patrol for unnecessary adjectives, adverbs, and prepositional phrases. They add bulk when every word counts. When you're sure you're done, have someone who doesn't know the story read the synopsis for sense.