Alex Spirriton was a ordinary boy from England who became a companion of both the tenth and eleventh Doctors. Like River Song, Alex and the Doctor meet in the wrong order: the first time the Doctor met Alex, the boy and recently worked with the eleventh Doctor to stop the macra, which is when the Doctor last has an adventure with Alex. The only point when their lives had followed the same linear direction was when Alex had been travelling with the Doctor in the TARDIS.