— Arnold Rimmer (RD: Fathers and Suns)
Pree is portrayed by Rebecca Blackstone, although she is incorrectly acknowledged in the episode's credits as "Rebbecca" Blackstone.
Recovered from a derelict ship (possibly the SS Trojan), Rimmer and Kryten install the sentient Pree on Red Dwarf in order to replace the silent JMC On-Board Computer. The ship's former artificial intelligence, Holly, is presumably still out of service due to water damage as indicated in Back to Earth.
Pree has the unique ability to predict a crewman's actions before they have undertaken them, in a similar fashion as predictive text on a cell phone. She studies security footage and crewman data to determine a profile of every registered crew member, and can then predict their actions, words, and thoughts even before they have even determined them themselves. Her predictions are never shown to be inaccurate during the events of the episode, and she even anticipated Rimmer's ineptitude well enough to actually actively replicate the botched repair job that he would have ordered on B Deck, although she is shown to be vulnerable when she misses an important piece of information.
During the events of the episode, Lister de-registers himself as a warning to his son, who happens to be himself, while drunk on GELF Hooch. Because of this, Pree no longer feels the need to provide him with oxygen, and forces him off the ship. Without any living listed crewmembers to bring home and protect (the Cat and Kryten not seeming to count, potentially because they are additionals), Pree orders the ship to fly into the nearest sun, considering it to have lost it's purpose and to have become merely space junk. Lister manages to jetpack back on board through the ship's scoop, and convinces Pree to uninstall herself.
Lister had previously attempted to register his son, once again himself, as another crewmember. Knowing this, Lister informs Pree that as soon as his file is done being registered his son would order her to uninstall herself. Because Pree is a predictive computer, and because her overriding mission is to ensure the efficient running of the ship and the prompt execution of the wishes of its crew, she agrees with Lister that she should uninstall herself immediately, rather than wait for the order to actually come from his son, who is of course himself.