Avengers 4: Nebula for emotional REUNION with Gamora? Karen Gillan and Zoe Saldana's clues

The latter was seen being brutally killed by Thanos (Josh Brolin) in Avengers: Infinity War but is known to be taking part in the current reshoots for the next film in Atlanta.

Also on set yesterday? Gillan, who plays her on-screen sister – one of the few survivors of the Snap in Infinity War.

Saldana took to her Instagram to share video clips of herself being covered in green, ready to reprise the role of Gamora; and also shared a picture to her main feed.

Gillan was also on Instagram talking about filming – where she confirmed that it was her final day of work on the film.

She wrote over a video clip of herself being put into costume and make-up: “Last day on avengers!!!”

The two being on location on the same day presumably means they will share some screen-time, although the nature of it remains to be seen.

While many Marvel favourites who perished in the Snap are already expected to be returning – Tom Holland’s Spider-Man, Elizabeth Olsen’s Scarlet Witch and Benedict Cumberbatch’s Doctor Strange, for example – theories have been a little more scarce as to how Gamora can come back.

One ongoing thought is that she could be ‘inside’ the Soul Stone, which is what Thanos obtained when he sacrificed her.

Other theories rely simply on time travel, while some thing she will only be seen in flashback and will not be coming fully back from the dead.

Another possibility is that the Quantum Realm will come into play somehow – after Paul Rudd’s Ant-Man was left stuck in it at the end of Ant-Man and the Wasp.

Avengers 4 is out next spring and its official title is yet to be announced – although a leak last week claimed it is Annihilation.

It follows hot on the heels of Infinity War’s enormous success: it broke multiple records on its way to a global gross of more than $2 billion.

Before Avengers 4 hits screens, viewers will be introduced to one of its new arrivals – Carol Danvers, aka Captain Marvel, whose own solo adventure is to be released in March.

It will mark Brie Larson’s official arrival into the MCU, after she was alluded to in the end-credits scene for Infinity War.

What part she can play in the overthrowing of Thanos and the return of various superheroes does, of course, remain to be seen – but it’s worth bearing in mind that she is being touted as Marvel’s most powerful character.

Avengers 4 is out on April 26, 2019 in the UK.