Shattered

Shattered is a main story quest in Fallout 4.

Detailed walkthrough
The Sole Survivor wanders through the ethereal strands of Kellogg's memory. Stepping from memory to memory, a scene plays out revealing a piece of Kellogg's life. In each scene, various things can be activated for extra story. The memories reveal that Kellogg does indeed work for the Institute, took Shaun from Vault 111, and shows that Institute uses some kind of teleportation to operate freely. The final scene reveals that Kellogg's current mission is to hunt down a runaway scientist named Virgil and that Virgil likely escaped into the Glowing Sea.

Upon conclusion of the final scene, Doctor Amari will instruct the Sole Survivor to interact with the television to leave the memory. Back in the Memory Den, speak to Doctor Amari about Virgil. When leaving the Memory Den, there is an optional conversation with Nick Valentine where he will offer additional advice about hunting Virgil.