In the second act of Avengers: Endgame, the team splits up into smaller teams in order to retrieve all the Infinity Stones and reverse Thanos’ deadly snap.
They do not agree on who should sacrifice themselves, so they end up fighting one another to keep the other alive.
Both Clint and Natasha are willing to give up their lives for the cause.
As the pair finds out on the planet from Red Skull, one of them must sacrifice themselves in order to obtain the stone.