During the infilitration into the Lobito Physics and Chemistry Lab, Alice supported Solid Snake via Codec and provided him with necessary information on his surroundings. Her psychic powers ranged from clairvoyance to precognition.
However, throughout Snake's infilitration it seemed that she herself had some secrets to tell - including the truth about her identity. In reality, Alice was in fact "No.16" - the result of a secretive project headed by Hans Davis and Dr. William L. Flemming. She was capable of using ACUA to control people's thoughts. It was Alice (No.16) who implanted the memories of Hans Davis into the mind of Snake, in addition she also controlled the hijackers who took over Flight 326. After Snake defeated Metal Gear KODOQUE, the memories of all the people she had controlled came back to her simultaneously, causing a shock which led to her collapsing, unable to resist the pain and resulting in her immediate death.