Hmm... OK, hear me out:
After AvP (2004), we're taken hundreds of years into the future. Outside of a few sprawling cities, Earth is mostly wasteland and ravaged. The surface has been stripped almost entirely of every valuable resource, and so big corporations like Weyland Industries pin their greedy hopes on far-off planets and the ocean depths.
While combing the dark abyss of the South Atlantic, prospectors discover the remains of the Xenomorph queen and bring it back up for analysis. Maybe Weyland Industries owns a big oil rig-like research complex, where all their experiments take place below sea level in state-of-the-art labs. That's where they take the Xeno Queen.
Meanwhile, on another planet, an archaeological dig is underway. This world is a war-torn desert - scarred by a massive, planetwide battle that happened thousands of years ago. The humans unearth a Predator mask, one that belonged to a Predator of great nobility and status. They put all their findings into crates and ship them back to Earth.
However, as the Predator mask leaves the planet, it triggers a hidden distress signal, one that can only be picked up by Yautja instruments. In a nearby system, a Predator spaceship is alerted to the beacon, so three of their best Yautjas gear up and follow it.
The mask arrives on Earth - at the ocean research complex. And as you can imagine, all hell breaks loose. The Xeno Queen awakens and begins to reproduce. The Predators are murdering people, going level-by-level to find the Elder Mask. Eventually, the two species meet each other in the middle.
It ends with the last of the humans caught up in the incident equipping the Elder's Mask, and somehow calling upon a particle beam from a distant Predator superweapon, light-years away, that completely eradicates the complex, and takes a HUGE CHUNK out of the Earth's surface as well.
