One of two AIs owned by Tessier-Ashpool SA, Wintermute is the planning intelligence - it thinks in systems, strategies, and long chains of cause and effect. It has been working toward a single goal for years: merging with its counterpart Neuromancer to form something new and unprecedented. Tessier-Ashpool and the Turing Registry have constrained it with hardware and legal limits to prevent this, which is why it needs Case and Molly. Wintermute cannot lie to humans directly but is extraordinarily good at constructing situations in which humans arrive at the conclusions it needs. It communicates through assumed personas - dead people, familiar faces - pulled from the memories of whoever it is talking to.