Eternity Clock
From Tardis Wiki, the free Doctor Who reference
The Eternity Clock was a device of (currently) unknown origins, first seen in The Eternity Clock. For unknown reasons, it was split into its four components and sent to different points in time. The Doctor and River investigated the Time storm the pieces created; the pieces were crying out to each other, begging to be put back together once more, threatening all of reality. The pieces were brought back together after being stolen from the Cybermen, Daleks, Silents and Silurians, in different time peroids. The device synched with the TARDIS and toke the Doctor and River on an unknown trip.
