The Timonic Fusion Device was a temporal weapon often theorised about, but thought to be impossible to create. A component of its construction was black light rods.
A secret project on Gallifrey called Project: Alpha built a prototype device. It was described as "napalm of the timeline" by Narvin and "a dirty, indiscriminate little weapon that should never have left the drawing board" by Braxiatel. (AUDIO: Weapon of Choice [+]Loading...["Weapon of Choice (audio story)"])
When the prototype was detonated, it destroyed the planet Minyos. The High Council covered up the incident by claiming Minyos had been destroyed in a civil war. Irving Braxiatel planted a data bomb in the Matrix in order to keep the truth about Project: Alpha accessible in case of an emergency.
However, history was altered when Torvald's servitors from Gallifrey's future went back in time and stole the device right before the first detonation. Not wishing to be responsible for the loss of such a powerful weapon, the team told Braxiatel that they had dismantled it. Very few Time Lords knew that the weapon had ever existed; even fewer knew that it was still operable. (AUDIO: The Inquiry [+]Loading...["The Inquiry (audio story)"])
The Timonic Fusion Device was acquired by Nepenthe of the subversive organisation Free Time, who attempted to use it on Grybon; however, the weapon was never detonated due to Free Time being unwittingly used as a pawn in a greater scheme put in place to discredit President Romana. (AUDIO: Weapon of Choice [+]Loading...["Weapon of Choice (audio story)"], Square One [+]Loading...["Square One (Gallifrey audio story)"])
After it was discovered that history had been altered, President Romana and Cardinal Braxiatel travel back in time and prevented the Timonic Fusion Device from being stolen. They returned to discover that the Timonic Fusion Device that was almost used on Grybon was a fake. (AUDIO: The Inquiry [+]Loading...["The Inquiry (audio story)"])
During the Last Great Time War, the Sixth Tamasan used a Timonic Fusion Bomb to destroy the Dalek Time Strategist's ship, before the Strategist escaped via emergency temporal displacement. (AUDIO: Restoration of the Daleks [+]Loading...["Restoration of the Daleks (audio story)"])