A Dark Brotherhood Contract is a writ of execution ordering the death of the Nerevarine.
While investigating the cause of recent attacks against the Nerevarine, speaking to any member of the Royal Guard prompts a visit to the Great Bazaar sewers. An entrance to Old Mournhold's Manor District is discovered, providing access to Moril Manor. In the north building Dandras Vules of the Dark Brotherhood is found with this contract in his possession. Following the ensuing battle, if the contract is discussed with the Captain of the Royal Guard, Tienius Delitian, he reveals that the identity of "H" is likely King Helseth Hlaalu.
The Bearer of this document, under special dispensation of the Night Mother, who has entered in a contract in perpetuity with H, is given special dispensation to execute %PCName, a %PCRace recently residing on the island of Vvardenfell. In accordance with all laws and traditions, the afore-mentioned personage will be executed in the name of H in the most expedient manner possible. All services of the Dark Brotherhood are at the disposal of the Bearer of this binding and non-disputable document.