"The greatest show on earth meets for one last time tonight in the Sunshine State," say Maggie Haberman and Glenn Thrush at Politico. "President Barack Obama and Mitt Romney have had two of the most memorable debates in modern presidential history," and with Romney the resounding victor of Round 1 and Obama eking out a narrower win in Round 2, this third and final debate, focused on foreign policy, could prove decisive. We've already rounded up suggestions for what Obama and Romney have to do to win the last debate. Now, here's what you need to know as you watch the Sunshine State showdown:

When is the debate, and how can I watch it?
It starts at 9 p.m. (ET) and lasts 90 minutes. It'll be held at Lynn University in Boca Raton, Fla., and as with the previous debates, will be broadcast live on the major networks — NBC, CBS, ABC, Fox, and PBS — and cable news channels CNN, Fox News, MSNBC, and Univision, among others. The debate will also be live-streamed online at the Commission for Presidential Debates' (CPD) own collaborative sites: AOL, YouTube, and Yahoo, as well as numerous other sites. See this list from GigaOm for online options.

Who's the moderator?
Bob Schieffer, a veteran journalist and host of CBS's Face the Nation. So far, neither campaign has raised any specific complaints about the 75-year-old moderator, says Dylan Byers at Politico, but "if there is one criticism already dogging Schieffer, it’s that he has no first-hand experience covering foreign affairs." And if past is prologue, partisans will gripe about Schieffer after the debate is over.

What's the format?
The debate is structured like the first one: Six 15-minute time periods, with each candidate given two minutes and then the remaining 11 minutes for discussion. In the first face-off, moderator Jim Lehrer didn't enforce the time limits very strictly, but Schieffer has an advantage Leherer didn't, says Politico's Byers: "Both Obama and Romney will be seated at a table on Monday night." That changes everything, says Janet Brown, the CPD's executive director. "It is a lot easier for a moderator seated with the candidates to use subtle ways to get them to recognize time limits." Scheiffer has also released a preliminary list of topics: America's role in the world, the war in Afghanistan and Pakistan, Iran and Israel, the "changing Middle East and the new face of terrorism" (which will occupy two of the six segments), and the rise of China. 

Will voters be swayed by a foreign policy debate?
The conventional wisdom has been that voters this year care about the economy, not foreign affairs, say Politico's Haberman and Thrush. Plus, the debate will have some stiff competition: The San Francisco Giants and St. Louis Cardinals have a decisive Game 7 playoff, and Obama's "beloved Chicago Bears take on the Detroit Lions (Romney's childhood hometown team) on Monday Night Football." But at least one poll, from Harvard University, found that 61 percent of Florida voters and 59 percent of Ohio voters consider foreign affairs — especially terrorism and Iran's nuclear program — one of the most important issues in this election.

Sources: CPD, Los Angeles Times, Politico (2), Presidential Election News, Washington Post