Complex sentence: Mary also has a younger brother, Roy Albright, that claims to have been abducted by aliens this completely freaks out the family, to this Sally and Harry take out the cornfield to "killroy" as the plan is called.
Split into simpler sentences: Mary also has a younger brother, Roy Albright, who claims to have been abducted by aliens. This completely freaks out the family, to this end Sally and Harry take out the cornfield to "killroy" as the plan is called.