The Greth's trial
The Greth's trial was the trial which occurred after the Greth failed to dislodge the Clock-People from Gallifraxion Four.
The Clock-People decided to place the Greth on trial for interference. This was a joke, as the Clock-People were themselves invaders to the planet, who had evaded detection by Galactic Heritage by overwriting the planet's entire timeline, welding themselves to its native lifeforms, instead of taking it over all at once at a given point in its history. The trial was led by the Clock-People's leader, Carvil the Resurrected. Predictably found guilty, the Greth was banished to the Void Between Worlds, where the Clock-People themselves had previously been trapped as a byproduct of "a great war".
However, the Greth ultimately made its way back to the universe with the help of another entity, (PROSE: Out of the Box) the Yssgaroth. (PROSE: Preternatural Nights) It later told its "life-story", including the trial, to the Preternatural Research Bureau. (PROSE: Out of the Box)