In Secret Invasion, Gravik has managed to harvest DNA samples belonging to Groot, Cull Obsidian, Frost Beasts, and Extremis soldiers in order to transform himself into a Super-Skrull.
Today's episode sees his people begin to turn on their unhinged leader, but his ultimate goal has started coming into focus. While Gravik and the Rhodey imposter are plotting to begin World War III by convincing President Ritson to attack New Skrullos in Russia, the villain also gives Nick Fury an ultimatum.
If the former S.H.I.E.L.D. Director brings the Harvest to him, he'll call off the attack and avoid plunging Earth into another global war.
So, what is the Harvest? Later in the episode, we learn that after the Battle of Earth in Avengers: Endgame, Fury sent a number of disguised Skrull operatives onto the battlefield to retrieve DNA samples of the blood spilt by the heroes that day.
As a result, Fury harvested samples from pretty much every single superhero who fought Thanos, including Captain Marvel. Gravik was among the Skrulls tasked with retrieving those and Secret Invasion's lead admits it was likely where the villain got the idea to turn himself into a Super-Skrull.
In other words, everything that's happened so far is Fury's fault and as the episode ends, he agrees to take the vial to Gravik but dons his trademark trenchcoat and eyepatch because the Nick Fury of old is finally back.
The fact Fury took those DNA samples is a good reminder of his duplicitous nature (don't forget what he did in The Avengers). However, if Gravik gets his hands on the Harvest, then he will be truly unstoppable and more powerful than every Avenger combined.
Needless to say, next week's Secret Invasion finale promises to be very exciting...