One possible script for the 2024 DNC.
Joe unexpectedly shows up just before they put Scamala's name into the ceremonial nomination show, goes up to the microphone and tells the convention that he didn't actually quit the race.
The document supposedly taking him out of the race was a fake, and his signature was also faked.
He accuses Scamala and her people of an attempted coup, and directs the Secret Service to immediately detain her and her staff. He further implicates Nasty Nancy, Crying Chuckie, and his old boss, Obummer, and has directed US Marshalls to arrest them all.
Pass the popcorn.
Yeah, this is all fantasy - but one can dream.