After Knull's invasion of Earth, Tony Stark used the corpse of a Celestial he took control of during the invasion and converted it into a wormhole generator powered by the Celestial's energy that led to a pocket dimension that civilians could evacuate to safety to during a crisis. He built the machine in a former Stark tech armory in Wundagore Mountain. However, the bunker was attacked by the Bruce Banner who took control of the Hulk. After Stark failed to stop Banner from entering the bunker, Banner planned to pass through the wormhole. Stark warned Banner not to as he hadn't finished with the math and there was no telling Banner would end up. Banner didn't listen and passed through the wormhole.