Thomas Reginald "Tommy" Brockless was born on 7 February 1894 in Blackley, Manchester. He was the son of Constance Bassett and Thomas Brockless. He fought for Britain in World War I, in the 10th West Yorkshire Regiment. In 1918, he suffered shell shock and was admitted to St Teilo's Hospital in Cardiff.

In 1900, his mother died.

While Thomas was at St Teilo's Hospital, mysterious time-shifts started to occur — fractures in the rift, meaning that two slices of time were superimposed and becoming confused. Torchwood Three investigated; though they could not determine at what point in the future the other slice in time existed, they recognised Tommy in one of the fractures and decided to put him in stasis and wait until the hospital entered the other side of the fracture.

Torchwood cryogenically froze Brockless; and once per year they brought him out of stasis for tests. The process gave him a unique perspective on the following century. As they had frozen his most recent memories, the shell shock was not an issue during these awakenings. In the 21st century, anomalous activity finally returned to the now-abandoned hospital and the crew of Torchwood Three sent Tommy back through the rift to 1918, so his life would be like a thread, stitching time back together again.

However, when he returned, his shell shock also came back and three weeks later, he was shot by a British Army firing squad for cowardice. (TV: To the Last Man)