The Body in the Brothel

The Body in the Brothel was a virtual representation of one of Arno Dorian's genetic memories, relived by a Helix initiate through the Helix Navigator.

Brothel

 * Woman's body - A young woman's body. Has been brutally whipped. Her hands are bound and she is covered in wounds.
 * Diary - This appears to be the Marquis de Sade's personal diary. It is filled with explicit and disturbingly violent sexual content as well as far raging philosophical musings.
 * Ropes and gag - Short ropes and a spittle-soaked gag, all stained in blood.
 * Spikes and hooks - Bloody instruments capable of puncturing human flesh.
 * Whip - A long whip with a tip flecked in blood. There is a maker's mark on the handle: 7 rue des égouts du Ponceaux.
 * Statement of Anna - Anna (prostitute): Noted that many men come through and, although she didn't see de Sade, it's possible he was there. Noted one customer stayed a very short time. Afterwards, two men arrived, but only one went into Suzanna's room.
 * Statement of Micheline - Micheline (Suzanna's friend): Claims Suzanna was a favorite of de Sade, who came around frequently. Claims she warned Suzanna about him. Noted that the objects in the room were typical of de Sade.

Churchyard

 * Statement of the Vagabond - Vagabond (Etienne Clavet): Saw two men meet on the night in question. One dressed up in livery. The other man went into a nearby building.

De Sade Villa

 * Letter to valet - "I'll meet you there and we'll arrange payment. 50 livres as discussed."
 * Statement of the Marquis de Sade - Marquis de Sade: Admits to visiting Suzanna "with some frequency," but not on the night in question. Claimed his valet would provide an alibi. Noted the appearance of a young man who subscribes to de Sade's philosophies. De Sade recommended Suzanna to him.
 * Statement of the Valet - Valet (Olivier): Did not know de Sade's whereabouts on the night in question. Noted that de Sade is careless and could easily leave his personal effects anywhere.

House

 * Mysterious letter - You have done exceptionally well to find with access to de Sade's personal effects. Under no circumstances are you to do the fatal deed yourself. We must avoid having suspicions raised on the Committee. Let our poor dupe do the work, he will be highly rewarded - 50 livres are enclosed. When all is done, de Sade will wither in jail and his immoral and pernicious influence on our citizens will be washed away like so much aristocratic blood. -- L.-A. de Saint-Just
 * Scrapbook - Contains a collection of scandalous newspaper articles about de Sade including his misadventures in Arcueil, Marseilles and at Lacoste.

Leather Shop

 * Delivery book - Legris: 44 Blvd St. Martin
 * Statement of the Leather Worker - The leather-worker (Jean-Marc): The whip was made by him. Supplies many things to de Sade. Mentioned student who wanted same items as de Sade, almost as if he worshipped de Sade. Delivery book has student's address.

Student's Hovel

 * Book: 120 Days of Sodom by Donatien A.-F., Marquis de Sade - De Sade's infamous volume describing the depravities of four libertines locked in a castle with several dozen victims of both sexes. Some of the abuses described are underlined.
 * Statement of the Student - Student (Quentin Legris): Claims he went to see Suzanna but lost his nerve and left. Also claims to have heard two men talking. One of them said, "After it's done, come meet me in the courtyard at St Nicolas des Champs and I'll pay you."

Brothel

 * Anna (Prostitute): Oh, god, there's men coming and going all the time! I didn't see de Sade last night, but he coulda been here, comes here a lot. It was too dark for me to see 'em proper, but there were some odd goings-on last night. One john came in but didn't stay long enough to really do anything. And then there were two men, but only one went into Suzanna's room.
 * Micheline (Prostitute. Friend of victim): Poor Suzanna! She was a favorite of that Citizen de Sade that came around so much. He never treated her proper. I told her, "Send him away!" But he pays so much. Look! Ropes, whip, that's de Sade all right. Randy bastard!

Churchyard

 * Etienne Clavet (Vagabond): Ah, sure, I'm here all the time. I've got nowhere to go. Who you lookin' for? I saw a couple fellas meet here late last night. One of 'em was dressed all fancy. Must be a servant, I overheard him mention his master, "the Marquis." Afterwards, the other man went into that building, right there. 

De Sade Villa

 * Marquis de Sade (Roué): Back to jail! It's all too delightful. Really - murder a girl? Those days are behind me. But I do enjoy the fuss. I did visit Suzanna with some frequency, but not last night. I'm sure my valet can confirm my whereabouts. There was a young man, some days ago. Perhaps rather too taken with my philosophies. I recommended Suzanna to him. It's not impossible he might know something.
 * Olivier (Valet to de Sade): I'm unable to say what the Marquis was engaged in last night. It was a rare night off for me. If any of his personal effects are missing, well he gets caught up in his "activities" and becomes careless. He could have left them anywhere.

Leather Shop

 * Jean-Marc (Leather worker): Sure, I made that whip. I supposed it could belong to de Sade, I sell him all sorts of things. But, you know, there's a student, strange fella, he wanted to buy all the same things de Sade bought - seemed to think de Sade is some kinda god or something. I've got his address in the delivery book. Let me see... Yes. Here it is.

Student's Hovel

 * Quentin Legris (Student): Suzanna? De Sade told me about her. I arranged a time and thought about all the things I would do to her. I started to lose my nerve, though, so I drunk a couple of bottles of wine. By the time I got there, I couldn't go through with it. I turned around and left.
 * Arno: Anything else?
 * Quentin Legris: I heard two men in the dark just when I was leaving. One of them said, "After it's done, come meet me in the church courtyard at St. Nicolas de Champs. I'll pay you there."

Case Summary
De Sade's valet, after years of witnessing scenes of debauchery and being subject to humiliations himself, was lured by an agent of St-Just to frame de Sade for a murder. The valet collected some of de Sade's personal effects, met with the St-Just's agent and went to the brothel where he murdered Suzanna in show of "sadism". After the murder, he met the agent in a church courtyard for his payment, where the vagabond saw both the valet and St. Just's agent.

Reference

 * Assassin's Creed: Unity