Silus Treatment

 is an unmarked quest in Fallout: New Vegas.

Quick walkthrough
Travel to Camp McCarran and enter the terminal. Go to the second floor. Go to the west end. In a room to the north is Carrie Boyd.

Speak to Carrie Boyd and agree to help her interrogate the prisoner.

Interrogate the prisoner and get him to tell about Caesar and the spy at the Camp.

Detailed walkthrough
Silus is held captive in Camp McCarran, and the NCR is attempting to interrogate him. He will not give information to the NCR, and interrogator Carrie Boyd is looking for help. She informs the player that the NCR does not allow torture of prisoners. The player can suggest a truth serum, beating the prisoner, or calling him names.

If the player has a high enough reputation with the NCR, Lieutenant Boyd will allow the player to go in and speak with the Centurion. The player will go in unarmed, unless the player's sneak skill is high enough to bring in holdout weapons.

The Courier can either break Silus or help Silus escape.

Break Silus
The Courier can speak with Silus or attack him outright. Should the player speak with Silus, a high enough speech skill will result in the legionary attacking. If your intelligence is at 8 then you can persuade him into thinking that you are working with the Legion and are here to assassinate him, this will result in him telling you all of his plans. After a brief fight, Lt. Boyd will come in again and ask Silus if he wants more. When the legionary refuses, the player will briefly speak to him again, and begin attacking once more. After a second round of fighting, Silus will talk, letting the player know that Caesar is sick and that there is a legionary posing as a member of the NCR at Camp McCarran.
 * Alternatively, through a series of either Speech or Intelligence checks, you can get him to reveal the same info without shedding any blood.

After the information is gained from Silus, you can no longer interact with him, and Lieutenant Boyd will pay you for your troubles.

If you leave the room after the first time you talk to Silus, you can not get back in, and further interaction with Lt. Boyd only result in her saying "Let's talk after we finish this up." and ending the conversation abruptly. There doesn't appear to be any way into the room at this point...

Help Silus escape
If you have already been invited to Ceasar's camp at The Fort you can begin by talking to him about how you're with the legion without lying. By doing this you can fake a fight and get him his weapon that he tells you is in the locker in the next room. After the fight when your sent back out get the weapon which is a silenced .22 pistol and when you go back in for the second round of interigation she will take all your weapons except the pistol. You will talk to him and give him said pistol and he will fake being uncouncious. Carrie Boyd will come back in and say it looks like he is all tuckered out and you and her will leave. On the way out she will tell the corporal to go clean him up and he will go in and tell Silus to get up. If you watch Silus will blow the Corporals head off and dress in his cloths. He will then sneak out and none of the NCR will know. You will not lose any rep. with the NCR because they won't know about it.

Note: After Silus is dressed as an NCR corporal he will not speak to you while he leaves.

Rewards

 * NCR Fame


 * 300 Caps


 * 325 XP

Bugs
A way to avoid this is to tell him to wait outside before you enter the interrogation room.
 * While ED-E is a companion, during the phase of the interrogation where Lt. Boyd speaks to Silus and ask if he wants more. ED-E may enter the room and start to attack Silus when he gets aggressive. When the quest is complete and you leave the room, ED-E will still be inside and will not be able to escape.
 * If the player is wearing Boxing gloves (Fallout: New Vegas) before Carrie Boyd takes your weapons from you then they will stay on your fists and remain so for the rest of the game. It grants the same effectiveness as regular unarmed blows and other weapons can still be equipped.
 * The door has many opportunities to bug - if you save after Boyd enters the room to introduce you (perhaps only as she is starting to walk out?) you will not be able to enter the room to interrogate Silus after she leaves. Also, if you decide you want to pummel Silus to death to earn points with Boone towards triggering his character quest I Forgot to Remember to Forget, Boyd may get stuck in the room afterwards, preventing you from talking to her again and completing I Put a Spell on You. (360)

Exploit: Getting all NCR Rewards
If you decide to go with the NCR route, Killing Silus to get the +1 with Boone and to get the Legion Centurion Armor will not allow you to get the payment reward from Boyd, and may cause problems getting to the next step in I Put a Spell on You, if you haven't already completed that quest. However, if you have a stealth boy and an explosive, you can get the +1 to Boone, the Legion Centurion armor that Silus wears, AND get the cash reward from Boyd.

First, make sure you have at least one follower with you, and then place an explosive (A regular stick of dynamite will work) in the follower's inventory. (Boone is recommended, since this exploit primarily exists to get the +1 with him in addition to the other rewards.)

Next, instruct Boone to stay close to you, and enter the interrogation chamber. (SAVE BEFORE YOU DO THIS.)

Move to the far side of the wall, as far away from the door as you possibly can. Boone will enter the room. Make sure you haven't spoken to Silus yet.

Remove the dynamite from Boone's inventory and drop it on the floor. By leaving the stick of dynamite on the floor, instead of keeping it in your inventory, you will able to use the dynamite inside the chamber. This normally isn't possible since your weapons are stripped from you when you enter. (Need confirmation of whether you can sneak explosives inside with a high sneak skill)

Once the dynamite is on the floor, leave it there, and then leave the room. As long as you haven't spoken to Silus yet, the door should be unlocked. Make sure Boone leaves the room with you. You have to get Boone out of the room before the door locks itself, or Boone will be stuck inside. Relocate Boone to a safe distance away from the chamber so that he won't engage Silus if he becomes hostile. If you have any other followers with you, do the same for them.

Finally, push Boyd close to the door. She should be positioned so that once you exit the chamber, she is already close enough to you that you can talk to her, without you having to move. (Basically, you need to be able to talk to her as soon as you possibly can once you leave the chamber.

Re-enter the room. To recap, you should have:

1: A piece of dynamite on the floor.

2: A stealth boy in your inventory.

3: Your followers are a safe distance away from the chamber.

4: You still have not talked to Silus yet.

5: Boyd is right next to the door.

If you have completed all five of these checkpoints, make a new save file.

Now you can proceed to interrogate Silus. The standard "beating" approach is the most effective for this. After the first time Boyd comes in to talk, she will harass Silus, and then walk out again. If Boyd moves away from her specified location during this part, leave the chamber and push her back. It is critical that she remains there. Next, walk up to Silus and continue beating him. Don't talk to him, just beat him. Talking to him before beating him at this point will cause Boyd to move AGAIN. (she magically teleports elsewhere.) Continue beating on Silus until he divulges his information about Caesar and the spy. The door should now be unlocked, allowing you to exit. However, DO NOT DO SO.

Look through the window and make sure that Boyd is in the correct spot. If she is not, revert to a prior save. If she is, push Silus until he is literally bumping up against the window. Grab the dynamite that has been laying on the floor this whole time, enter sneak mode, and make one last save file. Reverse-pickpocket the dynamite into Silus' pocket, and immediately run out of the room and talk to Boyd, BEFORE THE DYNAMITE DETONATES. (You will only have about a second or two to do this, you have to be quick.) She will give you the cash reward for completing the quest. End your conversation with Boyd, and the dynamite will now explode, killing Silus. If you positioned Silus correctly, you should be able to loot his corpse THROUGH THE WINDOW, even though you are outside. (You may have to abuse the third-person camera view to do this.)

At this point you should have:

- The cash reward.

- The next step in the I Put a Spell on You quest. (That is, if you haven't already completed that quest. I personally completed it BEFORE I did the interrogation, so this needs confirmation.)

- The Centurion armor.

- +1 to Boone's history points.

- A boost to your NCR fame

- A small amount of Negative Karma for Reverse-Pickpocketing the dynamite onto Silus

Killing Silus normally only gives the +1 to Boone and the Centurion Armor, and at the same time, gives you a PENALTY to your NCR Fame, as well as denying you the cash bonus. If you get the information from Silus before you kill him, you may or may not get the NCR Fame penalty and the next step for I Put a Spell on You. I completed the quest before I did the Interrogation, so I do not know if Silus triggers the next step or if Boyd triggers it. If you kill Silus after getting the information, Boyd's dialogue options concerning Silus disappear completely, meaning you likely won't get the next step in the quest, if Boyd is the one who gives it to you. (This needs confirmation.)

Interrogating Silus normally without killing him only gives you the cash bonus, quest information, and NCR fame, denying you the +1 to Boone and the Centurion Armor.

The only downside to using this method is the small amount of negative Karma you get from reverse-pickpocketing Silus, and the fact that this will likely take several tries to perform correctly, wasting a bit of your time.

This was performed and tested on the XBOX 360 version of the game. This exploit needs further testing and confirmation from other players in order to fine-tune the execution process and to confirm how it effects the I Put a Spell on You quest.