The Gate Maker was a portable device created by Skeletor from rare minerals that had the ability to create portals through space. As a result, it had the ability to travel to distant worlds allowing individuals, armies or even fleets to be transported between sites. Skeletor intended to use it initially to transport the Royal Palance at Eternos to Etheria in order to pit the heroes against Hordak.
Modulok who was operating the machine, however, was displeased in his servitude to Skeletor. After learning of Hordak, he decided to switch sides and stole the Gate Maker where he fled to Etheria. He went to the Fright Zone where he offered his service and the Gate Maker to Hordak. With it, Hordak intended to use the device to invade Eternia and prepared a fleet of vessels from the Evil Horde for the task. However, He-Man and She-Ra with the aid of Skeletor where the Gate Maker overloaded from the strain put on it.
It exploded and the gateway it made collapsed just as the Horde ships were travelling through it where they became lost on another world. Hordak demanded from Modulok to make a replacement but the new Horde prime scientist revealed that it was impossible as it was a one of a kind. As a result, the Horde leader demoted Modulok to the rank of chef and departed the scene.