Oscar lived on Madoc Road, Splott. He attended "The All-Night Zombie Horror Show" at the Regal Cinema. During the event, Leet - a "child of the Dellacoi" crashed on Railway Street an d lost its life-shell. The cinema was destroyed, and 63 of the 64 cinemagoers were killed. A symbiont, Leet sought refuge in Oscar's body and Oscar became the only survivor.
Following the incident, he spent the next three months in a coma in the Intensive Care Unit at St Helen's Hospital. He was fed through a tube and breathed with the aid of a respirator. He was bathed once a day and turned regularly to avoid the onset of bedsores. His mother visited him at least once a day. She would talk to him, read to him and play his favourite music, including Queen, Bon Jovi and Bruce Springsteen, in the hope that he would somehow respond.
Hearing the call of its life-shell, Leet used Oscar's most recent memories - those of "The All-Night Zombie Horror Show" - to create search units so that it could be reunited. Leet found itself unable to control them, sparking a zombie outbreak across Cardiff.
During the outbreak, Oscar was temporarily abandoned by the hospital staff when the hospital became surrounded by the creatures, which were guarding their controller. His EEG machine spiked and troughed and his body twitched and shuddered. Behind his eyelids, Oscar's eyes jerked and rolled and his lips released a low, wordless moan.
In the early hours of the following morning, Captain Jack Harkness, along with a black-haired girl, a smart man and a chubby man entered the Intensive Care Unit with Leet's life-shell. Under Leets control, Oscar's eyes snapped open and he stiffly got up out of the bed, ripping the IV tube from Oscar's arm as it made its way towards its life-shell. Leet oozed up out of Oscar's throat and entered the pod. The life-shell rose into the air, latching onto Oscar's forehead, from where Leet spoke through Oscar, and told the group what had transpired. Control of the search units had passed to Oscar, who remained unconscious.
A horde of search units blundered into the Intensive Care Unit. The life-shell rose from Oscar's forehead and vanished, as Oscar collapsed to the floor with a groan.
Deep in Oscar's mind, Leet instructed him as to how he could save the world. Oscar awoke from his coma and instructed the search units to stop their attack. He then grabbed a gun from the floor of the Intensive Care Unit, shot the glass out of the hospital window and ran at the empty space left behind.
Gwen attempted to stop him, but was grabbed by Jack. She watched in horror as he feel head first from the window. His broken body lay in a spreading pool of blood on the concrete floor below. Without their controller, the search units evaporated into stardust.
Oscar was buried in a Cardiff cemetery beneath a black marble headstone. A "pitiful straggle" of mourners were present at his funeral, including his mother. The inscription on his grave read: "My Beloved Son. Taken Too Soon". Jack and Gwen visited the grave, where Gwen placed a posy of snowdrops against the headstone. (PROSE: Bay of the Dead)
Oscar appeared unremarkable. Of medium height with sandy hair, he was slight, bordering on weedy and plain, bordering on ugly. He was a slight, pale figure with a sickly complexion. He wore pyjamas. Under the light of the life-shell, his skin looked cold and as hard as marble. After awakening from his coma, his eyes were shining and his face was serene. (PROSE: Bay of the Dead)