 After weeks of futile escape attempts , Springfield 's residents finally make a dent in the dome ; pointing out the damage , Cargill manipulates Schwarzenegger into ordering the town 's destruction . In Alaska , the Simpsons see an advertisement starring Tom Hanks for a new Grand Canyon on the site of Springfield ; realizing the town is endangered , Marge and the children want to go back to save it , but Homer refuses . The family eventually leave him for good . Alone , Homer is adrift on an iceberg , while Marge and the children are captured by the EPA after they are discovered by the NSA and Marge didn 't stay silent and blowing her and her family 's cover . After a mysterious Inuit shaman ( MacNeille ) saves him from a polar bear , Homer has an epiphany and decides to return to Springfield to save the town from danger . 
