Travellers passing through Union Station in downtown Los Angeles on Sunday might notice a slight commotion -- for one night only, it is doubling as the venue for the Oscars.

While passengers jumping on a train most likely won't get a glimpse past the tight security, here are five things that movie fans watching the 93rd Academy Awards from home should look out for: 

'Nomadland' sweep? 

Going into Sunday, Nomadland is the clearest best picture Oscar frontrunner in years.

So barring a dramatic shock, the question may be just how many Oscars Chloe Zhao's road movie can win.

If the heavily improvised film lands the prize for best-adapted screenplay early in the night, a serious sweep could be on the cards.

And Zhao -- who would be the second woman, and the first of colour to win best director -- could equal another remarkable record.

Nobody has won more Oscars in a night than Walt Disney's four in 1953. Zhao is up for golden statuettes for editing, screenplay, directing and as a producer for best picture.

Eighth time unlucky? 

Of course, there is a big difference between landing multiple nominations and actually winning -- just ask Glenn Close.

From 1983's The World According to Garp to 2019's The Wife, Close has been nominated but failed to win on seven previous occasions.

If she comes up short again on Sunday, she will be tied with the late Peter O'Toole as the Academy's most reliable runner-up.

Unfortunately, the odds don't look great for Close -- while her transformational performance as a tough-as-nails grandmother in Hillbilly Elegy was praised, the film drew widespread scorn.

#OscarsSoDiverse?

When last year's nominations were announced, it looked like years of activism and pledges for reform driven by the #OscarsSoWhite campaign had come to nothing -- 19 of the 20 actors were white.

But this year's crop of stars have set new records for diversity, including nine actors of colour on the shortlists, and the first Asian American ever nominated for best actor (Steven Yeun of Minari.).

Two women were nominated for best director, for the first time ever.

And it is not just the Oscars -- earlier this month, the Screen Actors Guild selected non-white winners in all four film categories.

That quartet -- Chadwick Boseman, Viola Davis, Daniel Kaluuya and Youn Yuh-jung -- could well repeat on Sunday.

McDormand three-peat?

Frances McDormand has long been an Academy favourite, and she anchors this year's frontrunner Nomadland with a characteristically unglamorous portrayal of a grieving widow living in an old van.

Frances McDormand delivers a speech after winning an Academy Award in 2018 for Best Actress. The Hollywood veteran could make it three wins this year. Photo: AFP

If she takes best actress honours on Sunday, she will become only the second woman in Oscars history to bag a trio of wins in that category -- after the peerless Katharine Hepburn, who has four.

The Oscar would put her at the pinnacle of a triple-winners actress club also including Meryl Streep and Ingrid Bergman, who each have two lead actress Oscars and one supporting actress prize.

Masks, movie shots and more?

Oscars co-producer Steven Soderbergh and his colleagues held a press conference last weekend where they set out their vision for a ceremony intended to look more like a feature film than a TV show -- without saying anything specific at all.

For instance, will the stars wear masks? 

"Masks are going to play a very important role in the story of this evening... If that's cryptic, it's meant to be," Soderbergh said.

With so much under wraps, one thing is sure -- the night is the first major Hollywood gathering in more than a year, and without pesky journalists and studio executives around to disturb them, many stars will be ready to party.

"After the show, we'll go to the post-show, probably more alcohol on the post-show, but it'll be free, so it'll be great," joked co-producer Jesse Collins.