On a cold Valentine's Day in Chicago, Amy White, a young widow who lost her husband to cancer, visits the cemetery and makes an unsettling discovery: a bouquet of fresh daffodils lying in front of her husband's grave. Curiosity grows into obsession as Amy searches for the stranger who left the flowers, while keeping her activities a secret from her live-in mother and seven-year-old son. The search leads to an unusual friendship that transforms her world and redefines her life.