Why Can't We Be Friends?

Why Can't We Be Friends? is a side quest in Fallout: New Vegas.

Synopsis
A group of escaped convicts that broke off from the Powder Gangers after the prison break have made headquarters in Vault 19. However, the group is divided amongst themselves on what to do and who to follow. Samuel Cooke, an anti-NCR revolutionary, and his group want to wage a war on the NCR, while Philip Lem and his group wants to surrender to the NCR as they see Samuel Cooke as overzealous and will only lead them to their deaths.

Walkthrough

 * 1) Speak with Samuel Cooke and/or Philip Lem in the overseers' offices in Vault 19.
 * 2) Enter the sulfur caves beneath the vault.
 * 3) Cooke's objective: Kill all the fire geckos within the caves.
 * 4) Lem's objective: Find a way to block off access to the sulfur caves. (requires 40 Science, 60 Explosives and 3 C-4)
 * 5) Other option: Blow up both the the Sulfur Caves and the Vault. (requires 50 Explosives and 5 C-4, also fails the quest)
 * 6) Report back to Samuel Cooke or Philip Lem.
 * 7) Ending options:
 * 8) Cooke: Ask Papa Khan about the Powder Gangers joining the Great Khans.
 * 9) Lem: Convince him to surrender the group to the NCR, or ask him about joining the Great Khans (Speech check of 40). Ask Papa Khan about the Powder Gangers joining the Great Khans.
 * 10) Report back to Samuel Cooke or Philip Lem.

Quest stages
For Philip Lem:

For Samuel Cooke:

Behind the scenes
The title of the quest is a cultural reference to the song "Why Can't We Be Friends?", by War in 1975.

Bugs

 * If following the Lem quest line, the map marker will tell you to go to the sulfur caves entrance (now blown up and billowing smoke) to find and talk to Lem about joining the Great Khans after talking to Papa Khan. Lem is actually located in the Overseer's Office, and if you've opened the stairs leading to the sulfur caves he can sometimes be found stuck there.
 * If you enter the Overseer's office from the elevator entrance (Hard lock) in the sulfur caves and open the Overseer's Office with the Average terminal, or just go through this route at any time, you may have some issues with your companions as mentioned above in less detail. When you ascend the stairs into the office your companions become confused and instead of following you up will run out the door back into the caves. If you are at the top of the stairs with a companion and run down they will run back into the vault. It is possible, however to keep your companions with you during this if you manually "push" your companion up and down the stairs. Just crouch and slowly move them and they will glide up, or down the stairs from your push.
 * This seems more like a path finding issue. Your companions will go back the way you came and reappear by your side a few minutes later, the same way they will if you jump from a ledge, (yes, it's an oddity).
 * If the player chooses to destroy the sulfur caves and the vault, but didn't kill Cooke personally, then the ending sequence will still show Cooke still alive and the Powder Gangers terrorizing the Mojave.
 * After speaking to Papa Khan for Cooke and returning with the news, it is possible to enter Lem's office through the main door (not the overseer tunnel) to see the piles of bloody entrails. Returning to Cooke will not trigger the dialogue where Cooke admits to killing Lem; he asks you once again to go and speak to Papa Khan on their behalf even though this is now impossible.
 * It is possible to re-enter Vault 19 on the PC version using the no-clipping command to pass through the mound of earth that appears over the entrance.
 * The option to blow up the caves may not appear.
 * If you have initiated the quest Oh My Papa and haven't triggered the conversation with Regis, the option to ask Papa Khan about Samuel Lem's group is not a dialogue option.