The Cure for Madness

Objectives

 * Talk to Astrid in the Dark Brotherhood Sanctuary
 * Search Cicero's room, reading the last chapter of his journal and obtaining the password for the Dawnstar Sanctuary
 * Travel to the Dawnstar Sanctuary, kill Cicero, then report back to Astrid

Sanctuary in Shambles
The Dragonborn is met by Gabriella upon arrival in the Dark Brotherhood Sanctuary. She redirects the Dragonborn to speak with Astrid immediately. Astrid states that Cicero went crazy and attempted to kill everyone before fleeing. She recommends searching Cicero’s room for clues.

In his room, on an end table next to his bed is the final volume of Cicero's Journal. All the previous volumes can be found on nearby elevated surfaces. When reading the final volume, it will provide details of the password and location for an older and unused Dark Brotherhood Sanctuary near Dawnstar. After letting Astrid know of the findings, she instruct the Dragonborn to kill Cicero. She provides the horse, Shadowmere, as a means of getting to him. Despite the fact that Shadowmere is unique in appearance, choosing to obtain him is not essential to complete the quest.

While in the Sanctuary, talking with Nazir can make three new contracts available: Contract: Kill Anoriath, Contract: Kill Ma'randru-jo, and Contract: Kill Deekus.

Tracking Cicero
Outside the Sanctuary is a black pool that resolves itself into Shadowmere. He can be ridden to Dawnstar or else the Dragonborn can fast travel there. Once there, Arnbjorn is sitting injured on the ground just outside of the Dawnstar Sanctuary. He tells of his injuries, saying they were from a fight with Cicero, but that he injured Cicero equally as seriously, so the Dragonborn should just "follow the blood" to find him. After suggesting that he return to the home Sanctuary, Dawnstar Sanctuary should be entered.

Once inside, Cicero can be heard asking whether the Listener has come, and then saying that Astrid has sent her best. The path is relatively linear. There are Sanctuary Guardians and Udefrykte, a unique troll, along the way, as well as several traps (a spear trap when crossing the bridge, a fire trap in the round room just beyond the bottom of the first set of stairs, and bear traps in the ice cave). While the Dragonborn proceeds along the path, Cicero makes comments.

The first real choice of paths comes in a room with a set of steps in the southwest corner up to a gate of metal poles (that can be opened by puling a chain at the botom of the stairs), a large round opening in the northeast wall, and a door in the southeast corner. The stairs lead back to an earlier part of the path, so they should be ignored for now. The southeast door is barred from the other side. The round opening leads to an ice cave (thich Cicero calls a "forced addition").

Through the cave is found the troll, along with numerous dead animals. At the other end is a wooden door that leads to a retracting pole gate (the chain to open it is on the wall to the right). At the bottom of the stairs is a hallway with coffins on either side. The coffins are mostly empty - a few have bloody rags or skulls. There is a master-locked chest in a dead end passageway to the left (south) with leveled loot. At the end, another set of stairs leads up to the right (north) to another retracting pole gate opened by a chain to the right. At the end of this hall is the barred door to the left (that can now be opened) and another door to the right that leads to Cicero.

Confronting Cicero
Cicero is found lying on the ground faking injury. He asks that his life be spared and that the Dragonborn lie to Astrid about killing him. Should the Dragonborn decide to let him live, there is no effect on the outcome of the quest nor the attitudes of the other Brotherhood members. It should be noted that if Cicero is spared in this quest he will become an available follower for the Dragonborn. If he is killed, his body can be looted for his outfit (the jester outfit on the table at the entrance is less powerful), some gold and a leveled dagger. If he is attacked, he will get up and fight back, revealing that he isn't actually injured.

Completing the Quest
Return to Astrid and inform (or lie to) her about Cicero's death. She will then thank the Dragonborn and suggest they hold on to Shadowmere "a while longer," in addition to starting the next quest, Recipe for Disaster.

Journal

 * Note: The objective to Behold Shadowmere appears in the journal after the Quest complete stage if it is never completed in the first place (i.e. if the Dragonborn proceeds directly to the Dawnstar Sanctuary)

Trivia

 * The Legend of Red Eagle may be found after descending the first staircase in the sanctuary. Just before the hallway out of the L-shaped room there is a bookshelf next to a chair and table to the right. The book is found on the lower section of the bookshelf. This will start the The Legend of Red Eagle.
 * It is possible to both get Cicero's armor and let him live, but you will need the Perfect Touch and Poisoned perks of the Pickpocket skill, as well as any form of paralyzing poison. To get his armor, Cicero can be pickpocketed, giving him the poison. He will become paralyzed shortly, allowing his impossible to nab armor to be grabbed without fail. Alternatively a Staff of Paralysis or the spell Paralyze can be used.
 * If the Ghost of Lucien Lachance is active while exploring the Dawnstar Sanctuary, Lucien will tell the player that it is not wise to kill Cicero, because the Keeper is a sacred position in the Dark Brotherhood. He says that "The Dread father does not wish this!"
 * There are two skill books located on a table if the left path is taken down the stairs after the spear trap. The books increase one handed and archery.
 * The Jesters Outfit can be picked up just as the Dawnstar Sanctuary is entered. A full set is on a table just to the left of the entrance. A better version can be looted from Cicero, if he is killed.
 * For those who dislike the chore of leveling the Sneak skill, this is the perfect opportunity to increase skill levels. Although time consuming, this quest has perfect opportunities to level this skill. After entering the sanctuary, the Jester Outfit can be taken, which will help with sneaking. After equipping the outfit, Cicero should be found but not killed . After speaking to him, moving to the corner directly behind him and crouching into the sneak position should allow the Dragonborn to be hidden. Once the Sneak eye says hidden, the corner should be faced, then walking slowly (or if the "Silence perk" is unlocked, walking at a regular speed) will eventually increase Sneak skill. This method is quite time consuming, but it works. (Hint: A rubber-band can be put on the controller, then the game left alone, and upon returning, the sneak skill will be leveled up. It is necessary to periodically verify that the Dragonborn is still hidden.)
 * Cicero's 500 gold may be taken twice. This can be done by pickpocketing him before attacking. [If the Dragonborn is caught pickpocketing Cicero's gold, Cicero will attack and talk about his ploy to trick the Dragonborn and reveal he's not really injured. However, if the Dragonborn sheathes his/her weapons, Cicero will accept the surrender and go back to his fetal position.
 * If Cicero is spared (just lying to Astrid upon return to the Falkreath Sanctuary, saying that he was killed), and the quest "Hail Sithis!" is completed, he will have the option to be a Follower. Inside the Dawnstar sanctuary, Nazir will state that he knew the Dragonborn wouldn't kill him. Nevertheless, Cicero is back.
 * If the Dragonborn decides to kill Cicero, the door can be unbarred across from the door leading to the room Cicero is hiding in. Then, back up onto the steps in the first room, sneaking and shooting Cicero with a bow from a distance will cause him to get up and immediately lay back down. The process can be repeated until he is dead.
 * Humorously, the Quest Stage ID for the objective to Behold Shadowmere is 666

Bugs
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