Which words and what punctuation on the sentence below makes it urgent and tense?

“Oh, Lord,” Mama groaned. “Stacey, get Mr. Morrison. Quick now!” As Stacey sped from the room, Mama’s eyes darted to the shotgun over the bed, and she edged between it and Uncle Hammer. Uncle Hammer was watching her and he said, quietly, “Don’t worry. I ain’t gotta use David’s gun… I got my own.”