US presidential hopefuls Hillary Clinton and Donald Trump will square up against each other in Las Vegas on Wednesday night in the last debate before next month's election.
This comes 10 days after a tense second debate in which Trump threatened to have Clinton jailed if he was elected. He has also since alleged that Clinton was on drugs during their last meeting, calling for a drugs test to be held before tonight's debate.
Fox News host Chris Wallace is moderating the third election clash at the University of Nevada, which will cover six topics including debt and entitlements, immigration, economy, the Supreme Court, foreign hotspots and fitness to be president.
Trump is facing a battle to win over undecided voters, with multiple polls showing Clinton is leading the race to the White House.
He's under even more scrutiny after various claims of sexual misconduct have come to light. Trump has insisted the allegations are "100% made up", while his wife Melania said they were co-ordinated by his political rivals, telling Fox News: "They want to damage the presidency of my husband."
The claims surfaced after the publication of Trump's lewd comments in a 2005 video recording, in which he talks about his fame allowing him to grab women by the genitals.
With less than three weeks remaining before Americans go to the polls, Trump has claimed the November 8 election will be rigged in favour of Clinton, tweeting that "there is large-scale voter fraud happening on and before election day".
His remarks prompted President Barack Obama to urge Trump to "stop whining", while a number of prominent Republicans have rejected claims of election rigging.
Since the last debate, Clinton has faced her own controversy following more revelations about her use of a private email server, which Trump has branded a scandal "worse than Watergate".
It emerged the US state department had asked FBI officials to lower the classification of a sensitive email related to an attack on the US compound in Benghazi, Libya.
The FBI notes revealed the discussion of a "quid pro quo" in trying to get the email reclassified. Both the state department and FBI officials have denied any bargaining took place.
The Trump campaign has said Pat Smith, whose son Sean was killed in the attack in Benghazi, will be attending the debate in Las Vegas as the Republican's guest.
Smith was a featured speaker at the Republican National Convention in July, where she delivered an emotional speech blaming Clinton for her son's death and accusing her of lying to families about what sparked the attack.
This is by no means Trump's only guest: Obama's half brother Malik will also be in the audience as a Trump supporter, telling the New York Post the Republican "can make America great again".
The 90-minute debate starts at 2am BST on Thursday, and is set to be explosive.