Two classic movie monsters are dragged into a new story. The film combines the monster-action with a bit of Indiana Jones type adventure.
I have not seen the 2021 “Godzilla vs. Kong”, but I suppose that the scientist we follow (Ilene) was already there in part one and perhaps she even picked up her adoptive child Jia in that film.
Jia is the last of an ancient tribe that was (I guess) wiped out in the previous film. She is somehow connected to Kong. The new film plays in a time in which everybody knows about King Kong and Godzilla and their movements are closely followed, above and below the surface of the earth.
Kong has moved to “hollow earth”, a kingdom below the surface of the earth, but as he is the last of his kind, he is not going to find and kindred species there. Meanwhile, Godzilla appears to have plans to gain power above ground. A group of scientists do their best to keep the two apart, as them fighting would cause great damage for mankind.
Apparently there are other “titans” (‘monsters’) and Godzilla uses them to gain power. Meanwhile the same scientists have to visit the “hollow earth” to find the reason for certain disturbances that may also be a cause for Godzilla roaming the earth. In the “hollow earth” they discover more than one yet unknown civilisation, one of which poses yet another thread.
In a massive spectacle of monsters fighting, only with a break every now and then when we follow the people in their quest through the subterranean rain forests, it is needless to say that it all leads up to a final battle.