During the Cardiff zombie outbreak, Keith caught two thieves - Gwen Cooper and Rhys Williams - attempting to steal his Mitsubishi Shogun from his driveway. He confronted the pair with a red squeegee mop. Gwen pulled a gun on him, while Rhys attempted to calm down the situation. As Keith backed up to get the car keys, he saw a group of zombies heading towards them.
Gwen advised him to go back into his house and lock the doors, but - upon finding out that he had a wife and daughter - decided to help him defend the property.
With the house as secure as they could make it, Keith and his family gathered with Gwen and Rhys in the front room. Keith gamely tried to make conversation, but the ceaseless thumping of the undead had them all on edge. When Naomi couldn't take anymore, Keith attempted to calm his wife down but she flinched away like he was a stranger.
A short while later, the zombies broke in through the window, and Gwen ushered Keith and his family upstairs. The Samuelses gathered beneath a wooden panel in the ceiling which led to the attic of the house. Gwen went first, followed by Jasmine and then Naomi. Clinging to the ladder, Keith found himself unable to move as the zombies ascended the stairs. Naomi shouted at him, which startled him free from his frozen state and he hauled himself into the attic, with Rhys close behind.
Safe in the attic, Rhys called his friend, Nobby, who had access to a Coastguard helicopter. Keith, Naomi and Jasmine made it safely aboard the helicopter with Gwen and Rhys and flew to St Helen's Hospital. There, Gwen rescued her fellow "spooks", Jack Harkness and Ianto Jones. The helicopter alighted on the hospital roof and Keith and his family waited with Nobby while Gwen, Rhys, Jack and Ianto went inside.
Rhys, with an embarrassed sense of shame, saw Keith as being just like him; his car was his pride and joy. When faced with a gun, Keith was both bewildered and scared. He admired Gwen whom he believed to be "a secret agent or something", telling his wife "She's got a gun and everything". He later referred to Torchwood as spooks.
Keith was frightened during the attack on his home, but attempted to put on a brave face, and looked to Gwen for instruction and reassurance. When the zombies broke in, he became startled, unable to communicate and froze to the spot - like a rabbit caught in the headlights.
By 2009, Keith was in his mid-thirties. When he first confronted Gwen and Rhys, he had tousled hair and an unshaven face which was rumpled with sleep. He wore a grey t-shirt, which stretched over his beer belly, and baggy black boxer shorts. He was not physically fit, and became breathless easily. (PROSE: Bay of the Dead)