How Little We Know

 is a quest in Fallout: New Vegas.

Detailed walkthrough
This quest is activated after talking to Yes Man or once Bye Bye Love is complete. Inside the main entrance to the Gomorrah, talk to receptionist on your left. Ask her about "the outstanding balance" on information to find out what's been going on in Gomorrah. She will tell you to find Cachino, a low level lieutenant, and ask him about suspicious Omerta activities. Another way to start this quest is as part of For the Republic, Part 2, you will be asked to get some information regarding the Omertas by Colonel Moore. She will then tell the PC to talk to Liza O'Malley to start this quest. This quest can also be given by Mick after asking him for work and he tells you that the Omertas have stopped buying guns from him

You need to find proof of Cachino's work he's been doing on the side that the Omertas don't know about to get him to talk. There is a journal in his desk in his room with evidence and another on his person that can be pick pocketed, his desk will be the one directly to your left as soon as you walk in his room. You can get the key from the receptionist. Once you return to Cachino and tell him you have his journal, he will offer you 100 caps to get the journal back, (or more if you have a high enough barter skill) He tells you about two people in the club that were brought in by the bosses as part of their plans, but doesnt know much about it, he tells you to talk to Clanden and Troike about specifics.

Clanden will not give you any clues or talk with you about what he does at all, even if you mention cachino sent you. If you go back and speak to Cachino, he'll mention he did some asking around and the bosses plans would be screwed if Clanden wasn't around, so he asks you to kill Clanden discreetly. Clanden will turn hostile as soon as he sees you draw a gun. Once you take care of him, report back to Cachino. Note: Killing Clanden before you are instructed to will result in failure of the quest but the player still receives the same rewards (positive karma, experience, etc.). If Cachino is killed by the player (or a companion) the same is true.

There's a hidden safe behind the wardrobe next to the bed in Clandens room. The lock can be picked or the key can be pickpocketed off Clanden. Inside the safe are snuff films Clanden has made. Taking the films back to Cachino will result in him telling you to confront Clanden with the tapes and blackmail him into either leaving Vegas or helping you. Confronting Clanden can result in him becoming hostile and attacking.

When you speak to Troike, start asking about the dead hooker, if you have the Medicine skill at 35 you can say that the story about him blacking out doesn't add up. The player can either find evidence that there was foul play by investigating the dead hooker in a hotel room, or by looking for other evidence (such as a blackmail note in big sal's office safe that proves the bosses set Troike up). Alternatively, you can talk to Big Sal and convince him to free Troike from his contract with a high enough speech or barter skill, this allows troike to be freed without having to investigate the dead hooker incident or find any evidence.

Once Troike has been freed of his contract, he will cooperate and tell you about his involvement with the Omertas. He'll tell you he was smuggling guns in through the NCR supply shipments, and you can discuss destroying the guns. He'll give you some thermite and a key to destroy the guns the Omertas have been gathering for their secret plans, or if your speech is high enough you can convince him to plant the thermite himself. The guns are behind a unique door in the hotel, look for two flamers, a sniper rifle, and two carbines (These will help later in the next part of the quest). Place the thermite on the guns and set off the detonator via the panel near the closest door to the room. If Troike plants the thermite himself he will get caught and rat you out before the Omertas kill him, but this wont ruin any of your objectives.

After you speak to Cachino about completing both objectives, he'll tell you the bosses need to be killed now. Luckily, they just put him in charge of finding out who's responsible for ruining their plans, and he'll lead you to a small room where the two bosses are. It is possible to convince Cachino to wait for your signal and he'll start shooting first with a speech of 80. If you didn't get the guns from the room when you used the thermite you can use the sawn-off shotgun Cachino gives you (or any holdout weapons you smuggled in) to kill the bosses. They'll ask you to have a seat, and the conversation will begin. They talk about how they know you've been ruining their plans and they want to kill you. At any point in the conversation you can start combat through a dialogue option, but it is possible with a speech of 80 to have Big Sal explain the whole plan to you, and you can convince Big Sal that Nero was helping you, and he'll start shooting Nero when combat starts.

Once the bosses are dead the quest is complete and Cachino will take over the casino, if you speak to him after the fight he'll offer you 50 Gomorrah tokens as thanks.

ALTERNATIVELY

If you inform the guard at the door to the Zoara Club that you have proof that one of their guys is dealing on the side, he will let you in to see the bosses. You can talk to Big Sal and offer him the journal for 100 caps or 5% of Gomorra's earnings if you succeed in a speech check. After that, Cochino is brought into Big Sal's office for a meeting where Button Man will shoot him. Talk to Big Sal afterwards to take over for Cochino. Big Sal will offer you a job aiding Clanden and Troike in their plans.

For Clanden, it means helping him kill "A large amount of people in a short amount of time" aka making bombs. You can make a nuke if you succeed in a science check (50 science) or chlorine gas. The Chlorine can be stolen from the Ultra Luxe casino. Troike will tell you that he is a gun smuggler and will inform you that he needs someone to retrieve a crate of guns stolen by the Fiends. Their location will be marked on you map. There are only three Fiends guarding a Crate of Stolen Weapons.

Return the chlorine to Clanden and the guns to Troike to update the mission. You will then be told to see Big Sal. Upon informing Big Sal of your having fulfilled his request to aid Clanden and Troike, he awards you 400 caps. You can also speak to him about gambling for 50 tokens.

Bugs
When speaking to Cachino before going to kill the bosses, selecting the "Wait" and "Ready" dialogue options may prevent Cachino from further interacting with the player. When trying to re-initiate dialogue, Cachino will only respond that 'there is no time to talk' meaning the player cannot tell him they are ready to go; and he will also remain in place and not lead the player to the meeting with the bosses preventing further progress in the quest including completion. Leaving Cachino there and attempting to finish to quest later will revert Cachino to previous lines of dialogue in which you can only ask about the bosses' plans, Troike, and Clanden. To note, this quest was undertaken before initiating or completing Bye Bye Love as the walkthrough indicates is necessary. It is unknown if this is related to the glitch. (Update, 360): Completing Bye Bye Love does not unlock communication with Cachino. ** This bug can be bypassed, by simply finding the small office where the meeting would take place, and killing the bosses, resulting in a quest complete message, regardless of cachino following you there. **

Sometimes, after unlocking the Very Hard locked door in which the Dead prostitute is located, she will get off the table as if sleeping. She will then use the default prostitute dialogue. Not quest-breaking as the dialogue concerning the prostitute occurs with Troike where there are other options for getting him to cooperate.

During the quest, when leaving the casino to The Strip before finishing the quest, the game will freeze with a black screen and only leave the radio music playing. (Is this only happening to me?)