Silus Treatment

Silus Treatment is an unmarked quest in Fallout: New Vegas.

Synopsis
The Legion is notorious for its fanaticism, to the point that legionaries are prone to committing suicide if they are at risk of capture. There are exception to that rule, however, and centurion Silus is one. While all of his subordinates and officers cut open their throats when the NCR prevailed over them, Silus was taken prisoner. He represents a rare opportunity for the Army to learn about the inner workings of the Legion and its current strategic situation, but the problem is that Silus has clammed up and refuses to speak - except to insult the interrogators. Lt. Carrie Boyd, tasked with making the centurion spill the beans, is at a loss as to how to make him speak.

Walkthrough

 * The quest is started by talking to Carrie Boyd at the interrogation room in the Camp McCarran terminal building, up the right-hand escalators. The lieutenant will explain the situation once asked about work. The player can suggest various options for making him speak, including applying a truth serum and torture. Boyd will reject the serum out of hand, due to the risk of overdose, but will entertain the idea of beating a prisoner of war up. While the soldiers are bound by regulations implemented during President Tandi's rule, the player, as a non-military asset unknown to Silus, is free to dislocate his jaw as much as they please.
 * Once the player agrees to help, Boyd will go in and introduce them as an outside contractor, then let them take over. Silus will be flippant about the whole situation. The player will be disarmed when they enter, sans any holdout weapons, and will be free to either make Silus talk or help him flee the cell.
 * If Craig Boone is present, the player can always kill Silus to gain a history point with him.

Opening Silus

 * The most straightforward way is to simply punch Silus. Boyd will come in and talk to Silus after the first round, then let the player punch him again. Silus will break afterwards, realizing the pointlessness of the situation. Silus will not attack and will merely defend himself by sidestepping and blocking.
 * The subtler way involves persuading him to talk through dialogue. The Speech checks are hidden, but Speech 50 is enough to pass all of them (Speech 30 with a copy of Meeting People). The checks focus on forcing him to drop his guard by insulting his martial aptitude and achievements, to the point that he starts divulging state secrets.
 * The subtlest way is to pretend to be a Legion assassin sent to kill him. This requires Intelligence 8 and allows the player to use Latin phrases to establish their credibility. The phrases are:
 * Corruptio optimi pessima (Corruption of the best is the worst of all) is derived from Moralia on Job by Pope Gregory I the Great, referencing the risk that Silus poses as a potential informant.
 * Legum servi sumus (We are all servants of the law) comes from Cicero and references the fact that Silus is bound by Caesar's law. It is an inversion of Cicero's aphorism, as the point of being servants of the law was liberation, not enthrallment.
 * Timeo Danao et dona ferentis (I fear the Danaans [Greeks], even those bearing gifts) is a quote from Virgil's Aeneid, referencing the Trojan horse and the player's infiltration of Camp McCarran.
 * All of the options allow the player to intimidate Silus by manipulating his fear of Caesar. He will try to get help from Boyd, who will simply state that she doesn't care if Silus dies. Then, when the player threatens him again, he will start spilling secrets, completing the quest.
 * Boyd will pay out the consultant's fee, and be a bit disappointed if the player did not torture Silus, while still admiring their competence.

Helping Silus escape

 * If the player has a positive reputation with the Legion or was invited to the Fort, then they can inform Silus of this fact and help him escape. Silus will decide to stage a fight and tell the player to retrieve his silenced .22 pistol from the locker in the adjacent room.
 * During the second round of the interrogation, Silus will pretend to fall unconscious. Boyd will then order Corporal Walter Hornsby to clean up the mess and get Silus ready for another round of interrogation. Hornsby will enter the cell and tell Silus to get up.
 * The centurion will promptly eliminate the corporal and put on his clothes as a disguise, then sneak out of the Camp. This does not cost the player any reputation with the NCR. Obviously, Silus will ignore the player as he leaves. Caesar will mention releasing Silus, primarily because it allows legionaries to find him and punish him.

Bugs

 * The player can earn infinite experience points by selecting the first Speech check, then the Intelligence check, and looping the first Speech option afterwards.
 * If Silus escapes, Boyd's scripts might break. This can be reset with the console command.
 * Loading the autosave made on transitioning into the save can break scripts or respawn weapons in inventory. It's also possible for Boyd to disappear. A manual save before tackling Silus is recommended.