The Strogg have at last located a source of the mineral steedium, which is required to power their large weaponry such as the fabled Big Gun. GDF have located and secured this mine along with a Big Gun. Strogg must activate this gun at once to take out nearby GDF defences. To do this they must break into the mine through an ice sheet on the surface, deploy a mining laser to access the steedium storage vault and finally take three crates of steedium to the Big Gun to activate and deploy it, obliterating the puny human food.