Final answer:
Four siblings enter the magical world of Narnia through a wardrobe and ally with Aslan the lion to defeat an evil witch.
Step-by-step explanation:
A quick summary of The Lion, the Witch and the Wardrobe is that it is a fantasy novel where four siblings, Peter, Susan, Edmund, and Lucy, are evacuated to the countryside during WWII. They discover a magical wardrobe that leads them to the land of Narnia, which is under the spell of an evil witch. With the help of a majestic lion named Aslan, they embark on a quest to free Narnia from perpetual winter and the witch's reign.