To borrow some imagery from Netflix show Stranger Things, this US presidential election campaign features two basic story paths which exist at the same time in parallel space.
Firstly, there's the daily news stream we consume of Trumpian outrages, lies and meltdowns, Twitter takes, cable TV punditry, conflicting polls and occasional Clintonian missteps and murkiness.
This is Republican Donald Trump's turf, where his blond thatch, bully boy bragging and dark, divisive language dominate.
In this volatile zone, the contest had become so tight in the past couple of weeks that Trump got to within a neck-breathing 0.9 per cent of Democrat Hillary Clinton's national poll average lead on RealClearPolitics.com before she eased ahead this weekend with 3 per cent breathing space.
Trump has increased his grip on several swing states over the past month including Iowa, Missouri, Arizona and Georgia and currently has narrow RCP leads in Nevada, North Carolina and Ohio. Florida is virtually 50/50 with Trump ahead by 0.1. The presence of two third party candidates - Gary Johnson and Jill Stein - is hurting Clinton's support. She is 3 per cent ahead in a two-way contest with Trump and 2.3 per cent ahead in the four-way assessment.
But then secondly there's also the (not so scary in this case) upside down parallel world, where Clinton has held a steady advantage for the past year.
It is where her forecast favouritism in various models floats between 60 per cent (FiveThirtyEight) and 80 per cent (Princeton Election Consortium); where she holds a ground game advantage of 789 staffers to Trump's 131; and where she essentially has to find only 28 Electoral College votes on top of the 242 that every Democratic nominee has won since 1992 to get the winning 270. Trump starts with a base of 102 and has to find another 168.
Clinton goes into Tuesday's first presidential debate with healthy leads in Pennsylvania, Virginia, New Hampshire, Michigan and Wisconsin although polls in Colorado are variable and her average lead is just 2.5. Vox's Matthew Yglesias noted that: "Convention bounces aside, the polling's been pretty stable".
In May, RCP's betting odds had Clinton favoured by 71 per cent to Trump's 29 per cent. At the weekend it was 68 per cent to 32 per cent - not much of a difference.
Adage.com reported that "spending by the Trump campaign, together with pro-Trump PACs, continues to be a small fraction of the spending we're seeing from the Clinton campaign together with pro-Clinton PACs".
And polls show a continuing pattern of voter intentions despite the changes of the daily news tape.
As confirmed by last week's NBC/ifWall Street Journalnf poll, Clinton leads with African Americans, women, those aged 18 to 34, people with university education. Trump has leads among men, whites and people without degrees.
The polls also show that while both candidates are unpopular, Trump is more so. The drip of negative stories about both continues to take a toll. In the NBC poll, four of the six issues that most worried voters about the candidates were to do with Trump.
The question is which narrative will be more influential going forward?
That has to be the underlying story which favours Clinton, especially the closer we get to the election - now just over six weeks away.
But each candidate has weaknesses which make the first debate both a crucial opportunity and (for supporters) a scary hurdle.
Sudden spurts in support or changes of fortune have happened before. In 2008 Barack Obama and John McCain were tied on September 17. The following day Obama had jumped to a 1.9 lead in the RCP average and never looked back, climbing to 7.6 in early November. In 1988 George Bush snr came back from 37 per cent to 54 per cent down against Michael Dukakis in July to win by 53 to 46 per cent.
Clinton's poll support has wavered during periods of negative news over her private emails, Clinton Foundation, 'deplorables' comment and health.
There are questions about just how solid her support is among young people, Hispanics, independents and anti-Trump Republicans. Millennials favoured Clinton's primary opponent Bernie Sanders and the fear would be that their turnout could be low. After strategically allowing Trump to shoot himself in the foot during the early stages, Clinton has begun trying to focus on policy in recent speeches. Sanders has been stumping for her.
THE US DEBATES
All are 90 minutes long
Livestreamed on YouTube and Twitter. Also on C-Span, CNN and Fox
9pm to 10.30pm ET, 2pm to 3.30pm NZT
1 Tuesday, Sept 27
Moderator Lester Holt, NBC
At Hofstra University, New York
Six time segments of 15 minutes each.
2 Wednesday Oct 5
Moderator Elaine Quijano, CBS
At Farmville, Virginia
Nine time segments of 10 minutes each
3 Monday Oct 10
Moderators Martha Raddatz, ABC and Anderson Cooper, CNN
At Washington University, St Louis, Missouri
Town Hall meeting format, half questions posed by public, half by moderators
4 Thursday Oct 20
Moderator Chris Wallace, Fox News
At University of Nevada, Las Vegas
Follows the same format as the first one
Will the third-party candidates be a fatal drag on Clinton's performance in swing states, or will their support fade by decision time?
Trump's key problem is expanding his support beyond his hardcore base. Although his prospects have improved recently with a more scripted approach, the unscripted Trump breaks out regularly.
His out-reaches to African Americans and women are unlikely to have shifted the needle. The fact that he is under-performing with white university-educated voters - a group Republicans traditionally carry - shows he is unlikely to exceed Mitt Romney's losing position in 2012.
Still, Trump has made poll advances while trying to be more disciplined since Clinton led by 6 per cent a month ago. RCP says that on current polling Clinton would scrape over the line with 272 - hardly a balm for Democrats' nerves.
Those old enough, remember how George W. Bush used debates to disarm enough voters to foil apparently more credible opponents in Al Gore and John Kerry.
Now, as the polling trend appears to be once more edging back towards Clinton, the debate in New York represents Trump's best chance to change up the race and jump ahead.
Clinton has more experience at one on one debating after her primary season with Sanders. But with Trump, anything could happen. He, of course, starts with the lowest performance bar to step over.
In the debate will he appear competent enough to allow exiled Republicans to smother their doubts and choose traditional tribalism over the traditional opponent?
Does Clinton find herself up against angry, say-anything Trump or calm Trump? And what will the millions tuning in prefer to see and hear?
The debate will be as much about the punditry spin about who 'wins' and whether that relates to how those in their living room couches see it.
The lessons of Clinton's Democratic convention poll bounce and her slight recovery last week amid terror attacks in New York and New Jersey provide a clue.
Voters will want positivity and presidential steadiness under fire from Clinton, and policy plans for the future. She will need convincing prepared answers on her emails, trust issues, the Clinton Foundation and her marriage.
Maybe she will manage to be relaxed enough to seem likeable.
For Clinton a good debate performance could turn her campaign's slight recovery into a surge towards that finish line.