Philip Lem

Located in Vault 19.

Philip Lem was an integral part of the NCR breakout, but believes the Powder Gangers should turn themselves back in since the gang won't be able to sustain themselves much longer.

He and Samuel Cooke are at odds over this, and Phillip will ask you to cut off the sulfur supply in the mines below the vault to prevent Samuel from getting resources to make more bombs. If you accept, it will prompt the quest "Why Can't We Be Friends" and he will give you a blue access key card allowing you to get into the caves.

Once in the caves, you will be able to choose whether to blow up the cave system or the entire vault/cave system (you must have 3 C-4 Plastic Explosives and an Explosives Skill of 60). If you cut off the sulfur supply and leave the vault in tact, return to Philip. Philip will thank you and mention that it is probably time for the Powder Gangers to turn themselves in. Agree it is the right thing to do and the quest will end.

Alternatively, you will have an option (Speech 40) to suggest that the Powder Gangers join the Great Khans. He will approve of this idea and want for you to speak to the Great Khans on his behalf.

Go speak with Papa Khan and he will agree. Return to Philip.

If you open the elevator from the sulphur caves to his overseer office (requires science 50 and lockpick 75) Philip disappears and is replaced by blood and guts spread around the floor. (Further proof required, this hasn't happened on two separate games (played on PC) even though the Overseer's entrance has been opened on both times.)