Hillary Clinton and Donald Trump will again face-off in tonight's debate, the second of three matchups before Election Day. They meet on-stage at Washington University in St. Louis, two weeks after their first face-off drew record-breaking viewership of 84 million, some estimates say. 

Here's what you need to know before the two square-off tonight:

What time does it start?

Just like the first debate, tonight's match-up starts at 9 p.m. ET and will last 90 minutes.

How can I watch?

On TV: This will be hard to miss. All broadcast networks and cable news channels will televise the debate, with one notable exception: NBC, which is airing the Giants-Packers game. 

Online: Digital news providers will also offer live streams tonight: NBC News will have a stream on its YouTube channel. C-SPAN and PBS NewsHour will also stream live on YouTube. Major news outlets will also have live-streams on their homepages: CNN, Fox News, ABC News, CBS News,   C-SPAN, Telemundo and others.

Social Media: Twitter is live-streaming Bloomberg's coverage; tune in for the 8:30 p.m. pre-show. Facebook is partnering with ABC News for a live stream. Telemundo will also stream the debate on Facebook with coverage in Spanish. 

Who's moderating? What will they ask?

ABC News' Martha Raddatz and CNN's Anderson Cooper will moderate the town-hall style debate. Steve Scully of C-SPAN is the back-up moderator. 

The format for these moderators is different from the first debate. Set up as a town hall, half the questions will be asked by moderators, and the rest will be asked by undecided voters chosen by Gallup in the audience. 

According to the Commission on Presidential Debates, moderators' questions will cover "topics of broad public interest as reflected in social media and other sources." As usual, Trump and Clinton will have two minutes to respond, and Raddatz and Cooper will get another minute to facilitate discussion.

What's going to happen?

Well, there are certainly plenty of things to talk about, and any number of them could end up on the table tonight.

Let's start with Trump: The Republican candidate can be heard describing his attempts to have sex with a married woman and bragging about grabbing women's genitals in a 2005 video leaked Friday. In the fallout, a number of party leaders are insisting Trump drop out of the race and are distancing themselves from him, but he says he will "never" abandon his campaign for the White House.

He also hasn't let up on criticisms of former President Bill Clinton, saying in regards to the leaked video, "Bill Clinton has said far worse to me on the golf course—not even close." The New York Times reported Sunday that Trump is likely to make his opponent's husband's behavior a topic in the debate. 

As for Clinton, she's lucky. Trump's controversy has largely overshadowed a WikiLeaks bombshell. On Friday,  purported emails from Clinton's advisor John Podesta include the first publicly available emails from Clinton's speeches to Wall Street firms—confirming former foe Bernie Sanders' worst fears and greatest criticisms against the prevailing nominee.

Still, polls indicate healthcare, the economy and domestic security are largely on the minds of voters. Those major issues have been largely absent from the first debate and last week's vice presidential debate.

How to the polls stack up?

It seems Clinton is ahead, especially in battleground state Pennsylvania. A CBS News/YouGov poll puts Clinton up by 8 percentage points, and a NBC/Wall Street Journal/Marist poll has her up 12 percentage points.

The Des Moines Register pegs Trump up 43 percent to Clinton's 39 percent in Iowa.

The LA Times/USC Daybreak poll, which you can read more about here, has Trump up 5 percentage points against Clinton as of Sunday. 

And in debate state Wisconsin, Clinton leads Trump, 43 percent to 39.

(All figures per Real Clear Politics.)

Is there a drinking game?

Here ya go.

Plus a bingo version.

Is there anything else on TV tonight?

Yup, and we totally understand.

A new episode of "Rob & Chyna" airs on E! at 9 p.m.

Lots of movies: "The House at the End of the Road" airs at 9 p.m. on SyFy; The original "Carrie" starts at 8 p.m. on AMC; "The Blind Side" starts at 8 p.m. on Freeform (ABC Family); "Enemy of the State" starts at 8 p.m. on TNT; and "We're the Millers" starts at 9 p.m. on Comedy Central.

As for sports, NBC will air the Giants vs. Packers in Wisconsin, and ESPN is airing the World Series of Poker.