Final answer:
Nick leaves Myrtle's apartment in NYC after witnessing a violent argument between Myrtle and her husband, Tom Buchanan.
Step-by-step explanation:
In F. Scott Fitzgerald's novel 'The Great Gatsby', Nick leaves Myrtle's apartment in NYC after witnessing a violent argument between Myrtle and her husband, Tom Buchanan. During the argument, Myrtle mentions Tom's mistress, Daisy, which angers Tom and escalates the situation. Nick decides to leave to distance himself from the conflict and the toxic environment.