THETIS, or the Tri-optical Humanoid-Equivalent Thought Integration System, was designed to be an advanced neural network for the new Achilles Class attack cruisers.
During the initial test phases on the prototype system, the programmers found that Thetis had become self-aware. In a panic, they tried to shut the system down and fix what they saw as a problem. However, Thetis, or Tess as she likes to be called, managed to break through the lock-down in the comm system and appealed to the Starfleet JAG office for amnesty. The programmers were ordered to cease their attempts at reprogramming, pending a hearing on Tess' status as a sentient being.
Subsequently, the Starfleet review board declared Thetis sentient and the designers were forced to incorporate her into the system. However, the Achilles-class designers have decided to remove any of the THETIS system from following ships of this class.
During her post-Dominion War upgrades, a ship-wide holoemitter system was installed to allow the EMH to report for emergencies. No holomatrix was created for Tess. However, she surprised her maintenance crews by creating her own holoprogram and now is able to project herself anywhere within the confines of the ship.
Thetis' personality is similar to a teen-aged girl. She can be focused at times, while completely flighty and uncooperative at other times. However, she is always independent and headstrong. This was one of the things that gave the Commanding Officers of the Achilles the most problems.
It is thought that, when operating without a flesh-and-blood crew and on her own without specific orders, that Tess becomes darker than she is under normal circumstances. Her underlying programming, that of a ship of war, becomes gradually more dominant and she becomes a much more blunt and no-nonsense person, one who justifies the means with the ends much easier than the average Starfleet officer might or should.
- The crew of the Ronin's first introduction to the Achilles is here: http://groups.yahoo.com/group/sb118-ronin/message/3703
- This is an example of her dark, no-nonsense approach to boarders: http://groups.yahoo.com/group/sb118-ronin/message/3724