Complex sentence: Convinced that they hold tremendous power, Cortex takes one of the crystals and returns to his laboratory to examine it, he discovers that the planets will soon align, creating a catastrophic solar flux that threatens to destroy the Earth itself.
Split into simpler sentences: Convinced that they hold tremendous power, Cortex takes one and returns to his laboratory to examine it. He discovers that the planets will soon align, creating a catastrophic solar flux that threatens to destroy Earth itself.