You and Gaster had gone out into the city to observe the chaos happening. Basically, Bete had literally created an aggressive giant pink blob created with FEAR that was now wrecking the city, because of course it is. Gaster was using his magic and you had an AMR. The pink blob knocked a building down, which it's debris fell onto you and Gaster, but Gaster used his magic to stop it from killing both of you. You were both trapped under the rubble while the creature kept causing havoc around the city.