As a child in 2008, Kelsey approached the Jacksons and became Maria's first friend when she noticed the moving vans on Bannerman Road. Almost immediately, she suggested they go into town on the free Bubble Shock! bus; the bus made a mandatory stop at the Bubble Shock! factory, where she and Maria met the Archetype. Kelsey was briefly held prisoner by Mrs Wormwood and used for her knowledge of Sarah Jane Smith. After leaving the factory, she warned Sarah about an attack from Davey and discovered Mr Smith in the attic.
Maria later described Kelsey as "backtracking like mad — saying there's no such thing as aliens". (TV: Invasion of the Bane) They were still friends when Maria met Uvlavad Kudlak, (PROSE: Warriors of Kudlak) and they kept in touch after Maria moved to the United States. Several years later, the two drank lager together on the South Bank of the Thames. (PROSE: Now or Thereabouts)
Before Kelsey's nineteenth birthday, (PROSE: Party Kill Accelerator!) her dreams were haunted by visitations from her clingy ex-boyfriend Ryan, a priest with an exploding glass face. Desperate to get rid of him, she joined Faction Paradox and was assigned the name "Ceol". She auditioned against several other Little Siblings for the rank of Cousin in a The Apprentice-style challenge overseen by Godfather Starch. Eventually, she beat Little Brother Dominic, became a Cousin, and used her shadow-weapon to kill Ryan. (PROSE: Now or Thereabouts)
When she was eighteen years old, Kelsey joined Theo Possible in the Zona Obscura Festival. Jimmy the Mandrill invited her to help him kill Iris Wildthyme, but Kelsey refused; later, she killed him. Upon her leaving the festival and being reunited with the Faction, Theo gave Kelsey his record box, and Kelsey joked that she could be called "Ms Funky Pair O'Decks". (PROSE: Party Kill Accelerator!)
Since no one deserted the Faction and lived, Cousin Ceol decided she had to die. Over a long period of time, she hid tiny slivers of her biodata, filtering out all elements tainted by the Faction and selecting pieces small enough not to arouse suspicion. All the while, she hid herself behind a "devoted acolyte" persona.
Ceol found a dodgy, backstreet cosmetic clinic on an insignificant posthuman colony that was scheduled to die in a burst of freak solar flares. She customised the clinic's genetic printer to weave her a new body from the stolen biodata and, once that was performed, she uploaded her consciousness to the new body a few hours before the flares hit. The shell of Cousin Ceol was left with the devoted acolyte persona, and she promptly signed up for a mission to Mohandassa during the House Military incursion, where she was inevitably lost. Cousin Chantelle said that the mission must have even impacted the histories of Ceol's ancestors and descendants.
In the new body, "Sojourner Hooper" barely escaped the planet as a refuge in the last transport ship. She then moved to Pluto, where she married Rex Agogô, formed a cymbiont bond with L-Event, and led a rebellion against the Company, after which she was elected the new president of PROTEC. However, she was blackmailed into joining Christèmas' plan to sabotage the Chance Coteries, where she discovered her rebellion had been puppet-mastered by Scacia De Ren. (PROSE: Weapons Grade Snake Oil)
After death, she and L-Event were resurrected in the City of the Saved, where she became Lady President of one of the factions during the City's Civil War. She ignored a message from Dominic. (PROSE: A Hundred Words from a Civil War)
Behind the scenes
- After the pilot episode of the Sarah Jane Adventures, the decision was made for the character to not return; no explanation was given by the BBC. Kelsey's role in the series was filled by Clyde Langer.
- "Ceol" is the name of the island from which the name "Kelsey" is derived.