College student Megs Devonshire sets out to fulfill her younger brother George's last wish by uncovering the truth behind his favorite story. What transpires is a fascinating look into the bond between siblings and the life-changing magic of stories.

1950: Margaret Devonshire (Megs) is a seventeen-year-old student of mathematics and physics at Oxford University. When her beloved eight-year-old brother asks Megs if Narnia is real, logical Megs tells him it's just a book for children, and certainly not true. Homebound due to his illness, and remaining fixated on his favorite books, George presses her to ask the author of the recently released novel The Lion, the Witch and the Wardrobe a question: "Where did Narnia come from?"

Despite her fear about approaching the famous author, who is a professor at her school, Megs soon finds herself taking tea with C. S. Lewis and his own brother Warnie, begging them for answers.

Rather than directly telling her where Narnia came from, Lewis encourages Megs to form her own conclusion as he shares the little-known stories from his own life that led to his inspiration. As she takes these stories home to George, the little boy travels farther in his imagination than he ever could in real life.

After holding so tightly to logic and reason, her brother's request leads Megs to absorb a more profound truth: "The way stories change us can't be explained. It can only be felt. Like love."