The Thinker
The Thinker is an early supercomputer that is able to control Rapture's security system and predict events at "the speed of thought". It is located in Rapture Central Computing, a location at the heart of "Minerva's Den". Wahl misused the Thinker to enrich himself by predicting sport scores and stock prices, while Porter tried to use it to replicate the mind of his deceased wife Pearl. Reed's addiction to Plasmids fueled an unhealthy obsession with the Thinker, and he manipulated it to frame Porter as one of Fontaine's spies, leading to his downfall. But unbeknownst to Wahl, the Thinker replicated Porter's personality and helped free him from storage. It now seeks to aid its creator (now known as Subject Sigma) on his mission to bring him and itself out of the rapidly flooding facility.