His last name wouldn't have been Goodspeed because Horace wasn't his father. So either Rom is Paul's last name or Amys maiden name. * Horace was his father, Ethan was born 3 years after Paul died, there is no way Paul is the father. * Ethan used the surname "Rom" because "Goodspeed" would carry a negative connotation among the Others, being surname of their enemy's leader and all.