Iodene Bruckheimer is a sixteen year old living in the fictional city Radon in the year 2183. In this century everyone lives in the sky in apartments on high platforms above the ground. Iodene is a Level Nine in Lethal Protection and regularly practises in one of the simulators in preparation for her Level Ten qualifying mission. Hafmium, Iodine's best friend, watches over her while she trains in the simulator because of the simulator not being probably tested. When Hafmium objects to Iodene doing the hardest mission in the simulator, she goes behind his back and does it anyway. This resulting into her not being able to stop the mission with only one life left. The only way she can stop the mission is to finish it without dying, something that has never been done before. And inside the simulation waits a lot of challenges.