Save Killian's life

In the Crash House area of Junktown, go to Darkwaters General Store. Talk to Killian Darkwater and head for the exit. As you do so, a man named Kenji should walk past you and attempt to assassinate Killian. If you help Killian kill Kenji you will open up the Get Gizmo's confession quest line.

Reward
400 XP.