Rise of the Planet of the Apes 2 (The Return)
Rise of the Planet of the Apes (2011) lends itself nicely for a sequel. Here is how I imagine the plot for the next installment.
No human on Earth will survive against the infection spread by that lab worker gone missing. All mamals, except for the enhanced monkeys will also perished sooner or later.
The first manned mision to Mars was a success if even just for those inside the provervial spaceship. All by themselves and having no contact with Earth, they eventually establish a thriving colony in the red planet and dream to return to Earth, although they fear something ominous has happened in their home world. They resist to think all humanity has lost interest in them and fear the worst, but really have no clue of what is really happening.
Back on Earth, enchanced chimps have continue to evolve with the help of ongoing research and development in neuro-drugs. They have all the world for themselves and natural resources aplenty. They don't care about what is left of humanity stuck in Mars, but they keep and eye on the marcian colony development. They don't want them back and no atempt to communicate with them is made. Even signals are encrypted to hide all ape communication from human ears.
But as apes evolve faster than the marcian human colony can develop, they become genetically more human and their imune system starts to reject enhancement virus. Eventually they find the only way to develop a cure and prevent their own extintion is to start tests on human beings as soon as possible. So a mission to Mars is set highest on the agenda to capture as many human beings as possible and take them back to Earth.
But it won't be easy.
To be continued ;-)