Nicholas Meyer directed Star Trek II: The Wrath of Khan and Star Trek VI: The Undiscovered Country. He wrote the screenplays for Star Trek IV: The Voyage Home and Star Trek VI. Though never credited for his efforts, Meyer rewrote much of the screenplay for The Wrath of Khan by combining several elements from earlier drafts. He is also largely responsible for the nautical influence that pervades The Wrath of Khan and its sequels, from the military essence of the red-jacket uniforms to the more heated and dramatic character of the battle sequences.