Complex sentence: Matt's arm begins to mutate due to an infection from the T-Virus, and before Alice has a chance to administer the Anti-Virus, Umbrella scientists seize both Alice and Matt. Dr. William Birkin orders that Matt be placed into the Nemesis program.
Split into simpler sentences: Matt's arm begins to mutate due to an infection from the T-Virus. Before Alice has a chance to administer the Anti-Virus, Umbrella scientists seize both Alice and Matt. Dr. William Birkin orders that Matt be placed into the Nemesis program.