Republican US presidential candidates will lock horns in the last party debate before the Iowa caucuses, knowing their absent front-runner, billionaire Donald Trump, will be trying to starve them of attention with his own rally.
Mr Trump's abrupt decision to boycott the debate has added a new layer of uncertainty to a race that has defied political convention.
He cited "unfair" treatment from debate host Fox News as his reason for skipping the contest and holding a rally instead.
"I don't like being taken advantage of," he said in an interview on Fox, signalling he was not boycotting the highly-rated network completely.
On Monday, Iowa residents will gather in schools, churches and even private homes to choose among the Republican and Democratic candidates battling to be their party's 2016 presidential nominee - the first in a series of state-by-state contests to choose delegates to each party's presidential nominating convention.
Some Republican candidates saw Mr Trump's move as a welcome opportunity to emerge from the long shadow the tycoon has cast over the race, while also hoping it might damage his standing with Iowa voters.
"I think it'll hurt him that he's not showing up in the Iowa debate four days before the Iowa caucuses," former Florida governor Jeb Bush told CNN.
Florida senator Marco Rubio said Republicans "don't have time for these kinds of distractions".
Mr Trump has led the Republican race nationally for months, to the surprise of many. In Iowa, however, polls suggest he is locked in a tight race with Texas senator Ted Cruz, a favourite of the conservatives and evangelical Christians who hold significant sway in the state's Republican caucuses.
Given Mr Trump's unpredictable nature, some campaigns were preparing for the possibility he could reverse course and take the stage in Des Moines after all.
But he moved forward with plans to host a rally just a few miles away that his campaign said would raise money for wounded warriors.
With Fox carrying the debate, other cable channels were likely to show Mr Trump's event, stealing away at least some viewers who would have otherwise watched the contest.
While earlier debates have been instrumental in the rise and fall of several Republican candidates, they have had minimal apparent impact on Mr Trump's standing. He has preferred to make his case to potential voters in national television interviews and on Twitter, and has often faded into the background in the debates.
Mr Trump's absence was likely to turn attention to Mr Cruz, a firebrand conservative disdained by many in his party, and Mr Rubio, who is hoping a third-place finish in Iowa could help him establish himself as the choice of more traditional Republicans.
Others on the debate stage will have their eye on New Hampshire, where they are hoping a strong showing in the February 9 primary will jump-start their White House hopes. Mr Bush, Ohio governor John Kasich and New Jersey governor Chris Christie have all devoted the bulk of their campaign resources to New Hampshire.
Also on the main debate stage are retired neurosurgeon Ben Carson, who has a loyal following in Iowa, and Kentucky senator Rand Paul, who was relegated to the undercard event in the last debate.
Mr Trump's Fox feud dates back to the first Republican primary debate, when moderator Megyn Kelly took him to task over derogatory statements he made in the past about women.
Mr Trump threatened to boycott Thursday's debate if Fox stuck with plans for Ms Kelly to moderate again, but said it was a sarcastic statement from the network that was the final straw.
That statement said the leaders of Iran and Russia "both intend to treat Donald Trump unfairly when they meet with him if he becomes president" and that "Trump has his own secret plan to replace the cabinet with his Twitter followers to see if he should even go to those meetings".
Mr Trump and his campaign manager criticised the statement as taunting and juvenile.