The Orphaned Hour
The Orphaned Hour was a Time Lord weapon that was part of the Omega Arsenal. It had the ability to send everything within a defined radius back in time.
The Orphaned Hour was damaged during the Last Great Time War. It was flung clear of Gallifrey's destruction and landed on the planet, Zoline, where it was found by three natives of the planet. The three men, who came to be known as "The Golden Triangle", used the Orphaned Hour to reset Zoline every thirty years, stealing the technological advancements that had been made in that time and them claiming the ideas as their own. After decades of use, the Orphaned Hour's damage became too great and the weapon was on the brink of explosion. The Eleventh Doctor found the device and took it into his TARDIS, where it was absorbed by the time ship's "heart". (COMIC: Strange Loops)