The ninth Democratic presidential debate kicks off Wednesday with a new billionaire onstage: Mike Bloomberg.

For the first time since his late entry into the race and after a $400 million ad campaign, Bloomberg will face five other Democrats eager to take him down in an unscripted environment.

But Bloomberg won’t be the only one to have a target on his back. The new frontrunner in the race, Bernie Sanders, is expected to face questions over his refusal to release medical records after his heart attack.