Complex sentence: Belle uses it to visit her childhood home in Paris, where she discovers a plague doctor mask and realises that she and her father were forced to leave her mother's deathbed when her mother succumbed to the plague.
Split into simpler sentences: Belle uses it to visit her childhood home in Paris, where she discovers a plague doctor mask. Belle realises that she and her father were forced to leave her mother's deathbed as her mother succumbed to the plague.