Pheeble Will

 is a quest in Fallout: New Vegas.

Bighorner rancher Walter Phebus and his wife, Ethel have traveled to New Vegas on the trail of big-name rancher/robber baron named Heck Gunderson. Walter is bent on revenge after losing land to Gunderson in a shady deal.

Detailed walkthrough
Initiate conversation with Walter Phebus near the Las Vegas Boulevard Station to find that he has trailed Heck Gunderson to the Ultra-Luxe casino. Walter tells you his troubles, and requests that you find out why Heck is visiting the casino. With a Barter check of 70, you will receive 400 caps for accepting this quest. Ethel asks that you to persuade her husband to let the matter go. To accomplish Ethel's purpose requires a perception of 7 and a Speech check of 75 (This will end the quest with an EXP reward of 375).

Speak with Heck Gunderson (accompanied by a bodyguard in the Ultra-Luxe casino) to find out that he is working out a food supply deal with the White Glove Society, and that his son, Ted Gunderson, is missing. Offering to help find Ted will initiate the quest Beyond the Beef, and finishing that quest by returning Ted alive will fail this quest. However, It is possible to finish both quests by choosing option 3 below).

Return to Walter with your findings. He will ask you to murder both Gundersons. The reward can be increased by 500 caps for Ted with a Barter check of 80 OR 1,000 caps for Heck with a Barter check of 90, or you may offer to just "take care" of them.