Here's what you need to know as the two square off at Washington University in St. Louis for their second of three scheduled debates.
When does it start?
As with all the debates, Trump-Clinton II begins at 8 p.m. and will last 90 minutes.
Where can I watch it?
It'll be hard to miss. All of the broadcast networks (except NBC, which will be airing the Giants vs. Packers Sunday Night Football game) will televise the debate, as will all the cable news channels. You can also live stream it on any number of websites, including KHOU.com
CNN's Anderson Cooper and ABC News' Martha Raddatz will be at the helm in St. Louis on Sunday night. Steve Scully of C-SPAN is the designated back-up moderator, a role he's playing at all the debates should someone fall ill.
Anything different about this debate?
There is. The format will be a town meeting, which means half the questions will be posed by the moderators, while the rest will be asked by undecided voters chosen by Gallup, according to the Commission on Presidential Debates. The questions from the moderators, the commission says, will cover "topics of broad public interest as reflected in social media and other sources." So, basically, they could be about anything. Trump and Clinton will have two minutes to respond, and Raddatz and Cooper will get another minute to "facilitate further discussion."
After this, what's next on the debate schedule?
Brace yourself, but after Sunday night you'll only get one more chance to see Trump and Clinton on the debate stage. That'll come Oct. 19 in Las Vegas, and Chris Wallace of Fox News will moderate.