David, a robotic boy—the first of his kind programmed to love—is adopted as a test case by a Cybertronics employee and his wife. Though he gradually becomes their child, a series of unexpected circumstances make this life impossible for David.

When Jesper distinguishes himself as the Postal Academy's worst student, he is sent to Smeerensburg, a small village located on an icy island above the Arctic Circle, where grumpy inhabitants barely exchange words, let alone letters. Jesper is about to give up and abandon his duty as a postman when he meets local teacher Alva and Klaus, a mysterious carpenter who lives alone in a cabin full of handmade toys.