The Amok was a puzzle for advanced, multi-dimensional entities. It was a small coppery, coin-like object with indescribable geometry. It was partly intelligent and had a need to be played, breaking down barriers and affecting people's minds to reach that goal. Though it tried to be played by humans, the Amok was too complex for humans to understand. Under the Amok's influence, humans would lose focus on other matters, become obsessed with "having a turn" and eventually go insane.
Circa 2007, the Amok was found in a bar in Cardiff, where it caused chaos when the people inside tried to play it, went mad and attacked each other to get a turn. Torchwood Three captured and contained it, but it still had a mental influence on the team. Owen Harper snapped, releasing the Amok and causing further mental decay for Torchwood. Mr Dine, who also detected the Amok, broke into the Torchwood Hub, solved the Amok and destroyed it. (PROSE: Border Princes)