Kill Neal

 is a side quest in the original Fallout.

Walkthrough
Once you have given Neal's Urn to Vinnie, he will ask for your help with killing Neal. Agree to go with him and you will be transported to the Skum Pitt. Once Neal and Trish are dead, you'll receive experience and quite a hefty karma drop.

Reward
300 XP and -6 Karma.