Ashley Davidson was a drug dealer who arrived in the village in September 2015, searching for the deceased Carly Bradley. Upon learning that Carly had been murdered and Trevor Royle had been accused, Ashley told Trevor that the debts Carly had now belonged to him. Meeting former prison inmate Theresa McQueen, whom she had shared a cell with, learned of Patrick's intentions to construct a special needs unit at Hollyoaks High School. Ashley blackmailed Trevor into helping her kidnap Patrick, but Robbie Roscoe informed Carly's father, police sergeant Ben Bradley, and the plan was foiled.
Holly Cunningham, believed to have called the police on them, was kidnapped by Ashley and Trevor. Holly maintained her innocence and Robbie soon found the pair, just as Ashley was preparing to give Holly a fatal overdose. Robbie threatened to call his brother, also a police officer, and Trevor released Holly to Ashley's dismay.
Trevor sent Ashley photographs of Sienna wearing the ring that Carly had stolen from her, leading Ashley to realise that Sienna had been part of Carly's death. Disguised as a police officer, Ashley managed to trap Sienna and her daughter Nico in her car and took them to a scrapyard to set the car alight with them inside. Nico attempted to escape and as Ashley tried to stop her, Sienna struck her with a petrol canister and left Ashley comatose.
In hospital, Ashley left Ben a threatening voicemail on the same day she was given a dose of potassium chloride by The Gloved Hand Killer. However, the identity of the killer was caught on video by Doctor Charles S'Avage, who was unable to revive Ashley after she suffered the resulting heart attack from the injection.