Stop Gizmo

Take Revenge on Gizmo is a side quest in Fallout.

Quick walkthrough

 * Get Gizmo's confession.
 * Deliver it to Killian.
 * Go with Killian to kill Gizmo.

Detailed walkthrough
To complete this quest, the player needs to first Get Gizmo's confession. Once delivered, Killian will offer the player to join him in killing his adversary. The player should accept; he is directed to Lars. Once spoken to, the player will be immediately transported together with Killian and Lars to Gizmo's office.

Gizmo will immediately enter combat and attack. He is stationary, but his melee bodyguard, Izo is mobile and dangerous. The player ought to focus on Izo first before killing Gizmo. Once both of them are dead, the quest is complete.

Reward

 * 600 XP
 * 500 bottle caps.