Captain Sam Hawkins was a UNIT officer who served under Brigadier Lethbridge-Stewart. He was an ex-boxer (PROSE: The Scales of Injustice) and, before joining UNIT, had served as quartermaster at the vault in Northumberland. (PROSE: The Forgotten Son) He was engaged to Corporal Maisie Hawke when he fought the Silurians at Wenley Moor. (PROSE: The Scales of Injustice)
He was part of the UNIT group sent to the Wenley Moor nuclear research facility to investigate the the strange power losses their. He was part of the expedition that went down into the caves after the Third Doctor was almost attacked by a dinosaur.
When Major Baker wounded a Silurian and forced it into the moorlands, Hawkins helped search for it. He later searched Squire's barn for the Silurian, where he and another soldier almost shot a chicken, believing it to be the Silurian. He was later in charge of communicating with the UNIT helicopter searching the moorlands, and reported to the Brigadier that the helicopter had seen John Quinn standing by his car in the "northwest sector of area two".
Hawkins was later part of the UNIT expedition led by the Brigadier that became trapped in the caves when Morka put a fake wall up, planning to kill them from lack of oxygen. The expedition was freed when the Doctor negotiated with the Silurian leader Okdel.
He was placed in charge of a group of UNIT soldiers at one of the cave mouths. Hawkins later went to look for Private Wright after Sergeant Hart lost contact with him, despite Hart's protests that they had been ordered to stay where they were. They eventually found Wright's body, but were ambushed by a Silurian, which killed Hart. He then returned to the research centre and told the Brigadier that Hart had been killed and the Silurians were advancing everywhere. He later found Private Upton's body and reported the death to the Brigadier.
While searching throught the wreckage of the lab that the Doctor had used to find a cure to the Silurian virus, four Silurians invaded the centre with the Doctor as their prisoner. Hawkins took up a defensive position behind the doorway, and tried to shoot at the Silurians as one of them tried to kill the Brigadier. One Silurian grabbed the Doctor to use as a living shield, while another Silurian used its third eye to kill Hawkins. (TV: Doctor Who and the Silurians)