There’s this mission where you have to go to a ferry that’s hiding under a cliff and holding loads of weapons and ammo. You have to protect it while it makes its journey across the lake to the cease-fire town owned by one of the factions. Stop other boats from sabotaging it and fix it if it gets damaged.
Once it reaches the area, the town erupts into a warzone and you have to escape. And then go around by land and protect the boat again once it reaches another spot.
This all happens in the open world. No cutscenes, no mission zones, nothing. It’s all fluid.