Megara

The Megara were floating, glowing orbs who upheld the statutes of Galactic law. They were sometimes referred to as Justice Machines.

History
The Megara were microcellular metallic biomachines. They could fly through the air. They communicated with each other using a special language. The Megara believed that "humanoids" were inferior because they were not totally capable of knowing the truth.

At one point, a galactic federation appointed them to uphold the law. The Megara found the federation in contempt of court and destroyed the galaxy. They were sometimes assigned to transport prisoners. When two of them transported Cessair and her servants, she escaped and they pursued her to Earth.

When Romana I was kidnapped by Cessair and taken captive aboard her ship, the Megara, (TV: The Stones of Blood) dubbed Megara One and Megara Two by the Fourth Doctor, (PROSE: Doctor Who and the Stones of Blood) were alerted to her presence after the Doctor went to rescue Romana. They put the Doctor on trial and sentenced him to execution. Through the trial, the Doctor was able to get the Megara to recognise Cessair, and they turned her to stone.

As the Megara brought up the matter of the Doctor's delayed execution, they suddenly vanished, returning to the ship as it was about to leave for Diplos, as the Doctor had preset the controls before he left and hoped it would give him "a couple thousand years' grace". (TV: The Stones of Blood)

Behind the scenes

 * The Megara were voiced by Gerald Cross and David McAlister.