伊達鍵は眠らない – From AI：ソムニウムファイル

One day, after The New Cyclops Serial Killings was resolved, internet idol Iris Sagan (known as "A-set") is abducted by a UFO and forced to participate in a perilous escape game called The Third Eye Game. Meanwhile, in another part of the city, a mysterious device is discovered. It resembles a coffin, and attached to it is a note that reads:

"Psync me"

Relying on a tenuous line of communication with the missing Iris, one man rises once again, determined to track down the UFO that should not even exist. Together with his partner, the AI-Ball Aiba, he sets out on a quest. That man...is Special Agent Kaname Date.

[From official website]

A spin-off entry in the AI: THE SOMNIUM FILES series.