The Time Agency was a group apparently based in the 51st century and employing Human Time Agents. It is unknown how long it existed, but it was shut down sometime in the 51st century. The Agents utilized wrist straps which enabled them to travel through time to go on missions of an unspecified nature. In the BBC Torchwood series, it is revealed that there are only seven Time Agents left from the original Time Agency, one of which is Captain Jack Harkness.