Complex sentence: Hermione first appears in "Harry Potter and the Philosopher's Stone" when she meets Harry and Ron on the Hogwarts Express, where she condemns Ron for his inability to perform a spell to turn his rat yellow.
Split into simpler sentences: Hermione first appears in "Harry Potter and the Philosopher's Stone" when she meets Harry and Ron on the Hogwarts Express. Here Hermione condemns Ron for his inability to perform a spell to turn his rat yellow.