The epic origin of a beloved holiday icon unfolds, as nine-year-old Klaas Krengel flees plague-ravaged Germania on a swashbuckling adventure across Medieval Europe to the remote ends of the earth, where he finds himself pitted against a gruesome host of adversaries, all resurrected from old Austrian lore. A bit of a spoiled brat, Krengel's only friend is an insidious counterpart called the Krampusz, a blue-furred monster who suffers from a pronounced hoarding disorder. Vexed by his half-brother's lifelong privilege and pampering, the Krampusz enjoys nothing more than imperiling the boy through calculated misdirection, ultimately trapping him in the bottomless depths of the enchanted "Sack of Shadows." Therein, a fantastic realm of weird and warring races demands a showdown between Krengel and its tyrannical ruler, a horrendous witch who alone holds a key to the connection between Krengel and the Krampusz.