After discovering that a strange planet is hurtling directly towards Danville, Phineas and Ferb set out to avert a disaster, while Buford looks forward to making contact with its alien race. Candace cannot bust them until midnight due to signing a contract known as the "Bust Accord" so she anxiously waits until the time comes. Meanwhile, Dr. Doofenshmirtz uses a Sphere-Attract-inator to try and steal the world's largest ball of twine.