Colonel Freeman Lifford was part of an archaeological dig to a 3000-year-old Surene tomb in the vicinity of Ur in Lower Mesopotamia in 1924. He couldn't swim.
He asked Daphne Garsington to enter the tomb first as she was the smallest person on the team and could fit through the gap.
Not believing women could amount to much, he thought that Bertie Potts and not River was Professor River Song.
Following River's instructions, he climbed a tree and saved her from the flood by extending her a pick. He was the only survivor from the dig who saw saline drones, as well as humans and animals contaminated by them. River explained it away by desert sickness and hallucinations. She asked him to inform the families of the deceased, Archie Ferrers, Daphne Garsington and Bertie Potts. (AUDIO: The Boundless Sea)