Orb of the Emissary
The Orb of the Emissary was the tenth orb sent out of the Bajoran Wormhole by the Prophets. It was originally believed that only nine orbs existed. It ended up buried in a desert on Tyree. It can only be opened by the Emissary.
When Dukat was possessed by a Pah-wraith in late 2374, all of the nine orbs went dark and the wormhole collapsed, leaving Benjamin Sisko and the Bajoran people unable to contact the Prophets. (DS9: "Image in the Sand", "Shadows and Symbols")
Months later, in 2375, Sisko received a series of visions that allowed him to locate the orb. Once he knew what he was looking for, he was attacked by a member of a Bajoran cult that believed that the Pah-wraiths were the true prophets.
While attempting to retrieve it, Sisko was sent a vision by the Pah-Wraiths reminiscent of his previous visions involving himself in the role of Benny Russell. The nature of the vision was intended to dissuade Sisko from retrieving the orb and using it, but Sisko successfully accomplished his task.
When the box containing the orb was opened, the Prophet that had previously inhabited Sarah Sisko's body was released from it. The Prophet returned to the wormhole, cast the Pah-wraith out, and restored the wormhole and the other orbs. (DS9: "Shadows and Symbols")
