Mechanoid Doomsday Fleet
The Mechanoid Doomsday Fleet was the last line of defence for the Mechanoid Unity. They were kept in stasis on a remote Mechanoid world where they were being stored in case of an emergency.
The fleet itself consisted of a Neuronic class battle cruiser, a Solar Plexus class battle cruiser along with seven other craft with unknown configurations.
The rest of the galaxy learned of the fleet's existence when a renegade AI from the Mechanoid defence algorithms suddenly separated itself from the unity collective and broke free from the control of the Mechanoid Hyper-Brain. This renegade AI, known as Executor Vallrisz activated the doomsday fleet and was apparently driven by dreams of individuality from the collective. The Mechanoid authorities explained the appearance of this renegade defence algorithm as simply "something that had gone terribly wrong in the system and thus had caused an accident".
As the Executor Vallrisz - program took over the ships of the fleet, the Mechanoid Unity requested the Gigerdi Alliance to send assistance in dealing with the threat: a small task force from the 7th fleet was assembled and embarked on an unknown journey.
It became clear quite early, that the Gigerdians had absolutely no idea about the size and magnitude of the threat. As the Gigerdian forces started to combat the doomsday fleet, they quickly realized that it took a little more than your regular handful of ships to deal with Executor Vallrisz's threat: thus Inter-Stellar Alliance ships were tasked to assist in the plan that the Gigerdians and the Mechanoids devised to defeat the AI.
The plan worked, but the ensuing battle was extremely costly to the Mechanoids. The flagship of the doomsday fleet was destroyed along with five other vessels. Two of the ships from the fleet were handed back to the Mechanoid Government.