The next morning when they gathered on the bluffs(,) their excitement grew as

they saw Sandburg approaching the actor(.) NO BUT. They were soon puzzled when

they saw Sandburg look, bow, and continuing on(,) “what happened?”

Kinda sounds like a big run-on sentence..and you need to place appropriate commas in areas, and take out periods in others. The second sentence naturally sounds better if you take out “but” and make it into a new sentence..but i could be wrong, and it may just need the period before BUT if it’s asking for one change.

They saw when Sandbrug approaching the actor but they were soon puzzled.

They saw sandburg look,bow, and continued on.

Their excitement grew as they saw Sandburg approach the actor but they were soon puzzled when they saw Sandburg look, bow and continue on.

“What happened”

should be on a new line

well im not sure

it depends

what tense is it meant to be?

past/present?

the last one has conflicted tense