4 gegen Z (spoken Vier gegen Zet, also written as 4><Z, lit. "4 against Z") is a German children's television program shown on ARD and KI.KA in which four children are appointed as "Wächter" (guardians) by their deceased aunt Hedda to prevent Zanrelot, the "Herrscher der Finsternis" (lord of darkness) from leaving the underworld and gaining control over Lübeck. As of September 2006, two seasons of 13 episodes each have been broadcast. The show's success has sparked the creation of a total of 6 novelized versions of the television episodes.