A Crack in the Slab

A Crack in the Slab is the seventh mission in Dishonored 2, in which either Corvo Attano or Emily Kaldwin must navigate through Aramis Stilton's manor where reality has been distorted, and discover Delilah Copperspoon's secrets from an event three years in the past.

Mission
''A strange ritual was performed three years ago in Aramis Stilton's Manor, involving Delilah Copperspoon and her followers. Once inside, find out what you can about Delilah's secrets.''

Mid-mission
Now that you’ve learned Delilah’s secret, make your way back to Anton Sokolov, waiting aboard the skiff.

Details
The manor Corvo or Emily must explore has been sealed for three years after an occult event and now lies in ruin. Their powers will not work inside, and the Outsider appears at the beginning of the mission to give them the Timepiece. This artifact can show the manor's past timeline, and allows them to shift between the ruined present and the lavish past, where guards are still protecting this refined place.

As the protagonist progresses through the manor it is revealed that the Duke and his party are staying in Stilton‘s study, while Aramis Stilton himself can be found in the backyard. It is also revealed that the study is protected by a combination lock and the only copy of the combination is listed in Stilton‘s notebook which he keeps with him at all times. Both the study and the doors to the backyard are located at the far end of the manor and can only be accessed from the past.

When reaching the backyard, Corvo or Emily will also be given the option to decide Aramis Stilton‘s fate, potentially changing the present timeline. There are three ways to deal with him: After obtaining the combination from Stilton‘s notebook Corvo or Emily will be able to enter the study where the secret of Delilah‘s immortality is revealed. After leaving Stilton Manor the Outsider will pull Corvo or Emily into the Void and explain how Delilah managed to escape the painting she locked herself into 15 years ago.
 * Render Stilton unconscious. When knocking Stilton unconscious, either by choking him or using a sleep dart or stun mine, he will survive the night unharmed. He will keep ownership of his manor, performing several changes to it over the next three years. He will also keep supporting the miners and their families. This will result in an overall better future.
 * Kill Aramis Stilton. When killing Stilton, his home will be bought by Baron Caruso who will renovate it and then put it up for sale as Caruso Manor sometime later. The manor won‘t go to ruin, but aside from two rat swarms it will be abandoned. The miners will also stop receiving support from Stilton, resulting in an overall darker future.
 * Leave Stilton alone. When Corvo or Emily decide not to interact with Stilton at all his fate will not change. He will participate in the ritual and lose his sanity. The manor will go to ruin and the present the protagonist started from will not be changed.

If Stilton has been saved from the ritual, Corvo or Emily will be able to meet Lucia Pastor once more. She now lives in the ground floor apartment below where Meagan Foster was waiting in the previous mission. When talking to Lucia she will recognize the protagonist and suggest that someone inside the Grand Palace may be willing to help bring the Duke down.

Special Actions

 * Under the Table - Lifted Aramis Stilton's Master Key while hiding under the dining table.
 * Temporal Investigator - Reached the Study without the door code.
 * A Mind Made Whole - Saved Aramis Stilton from seeing beyond the world.
 * Leaky Basement - Found the Rune in the flooded basement.
 * Collapsed Balcony - Manipulate time to collapse the balcony.
 * A Better Today - Visited Aramis Stilton's office in the altered present.

Trivia

 * People killed in the present will still show up in mission statistics if that present is later erased by killing the past Stilton or rendering him unconscious, so this should be kept in mind when attempting a clean hands run.
 * Stilton will vanish in the past once the séance room is visited, making it impossible to change his fate afterward.
 * The achievements Under the Table, Flooded Basement and Dilapidation are all earned during this mission.
 * These achievements are the same as the special actions Under the Table, Leaky Basement and Collapsed Balcony, respectively.
 * The time travel aspect of A Crack in the Slab originates from the level Outer Persephone of BioShock 2, a game Arkane Studios worked on. A few scripted events allow the protagonist to instantly jump from a lavish section of the level to a terrifying-looking version of it while remaining on the same map. This inspired Christophe Carrier to make a level where the player could control time travel and explore the same map in different eras. He realized that this was the perfect game mechanism to show to the players the ritual that brought Delilah back into the world.
 * This mission is actually three maps, piled on top of each other, and the two alternate present (Stilton didn't assist the ritual) are the same map with minor changes. The Timepiece offsets the protagonist's position between two of these maps. If Stilton is either killed or knocked out, the Timepiece instead shifts them to a different "layer", appearing as a different version of the map. The trick to switch one present for another uses the same system as chaos to determine if the player didn't interact with Stilton in the past.
 * Designing the time travel puzzles in the mission was hard for the developers, who wanted puzzles hard enough to challenge the players but easy enough so the players would not go online to find the solution.
 * Originally, the developers planned to remove most of the protagonist's powers but leave Blink and Far Reach. This was later changed to leaving only the passive abilities active as the time travel mechanic was deemed to be interesting enough.
 * The map of the Dust District, when exiting the manor and only if Stilton was saved from the ritual, contains a set of street signs for "Legal District" and "Docks". Those signs are reused from Dishonored and were also present in a pre-release version of the map for the Dust District mission.
 * This mission's working title was "The Bunker", as seen in the game's files.
 * In the recreation of the séance room in the Void, a painting of a dishevelled Stilton can be seen disintegrating if he was knocked out.