Spies is a quest in The Elder Scrolls IV: Oblivion. Mythic Dawn agents have discovered the location of Martin and are spying on activity in Cloud Ruler Temple. Captain Steffan and his men have noted their activities, and these spies must be eliminated before they take action.
There are a few Mythic Dawn agents outside of Cloud Ruler Temple that the Hero will need to eliminate. It's best to do this at night when they have the element of stealth. The spies reside by the nearby Rune Stone.
Once they have eliminated Jearl, take her key and investigate her house in Bruma. Find the basement and find her orders from Ruma Camoran. They will discover the Mythic Dawn's plans for Martin and Bruma and if leaving through the caverns after reading the note it's possible to catch up with Saveri Faram, the second agent. Talk to the Countess in Castle Bruma, Captain Burd and follow-up with Jauffre.
The beggars will say that they saw someone else in the house but this information is all but useless. The second agent will be at the Stone after 1–2 days if the Hero didn't catch up with her.
Follow the quest marker and talk to Captain Burd in Bruma, then the other guard next to him. He will tell them to go and check out Jearl's house. The spies won't be there during the night so arrive during the day and kill Jearl and the other spy in her house.
Take the keys off Jearl's body, then proceed into the basement (through trap door in floor); take the orders before entering the cave. They are on a table in between the trap door back upstairs and the door into the caves. Return to Jauffre.
It is also possible to run right into Jearl on the street when first entering Bruma, in which case she may attack the Hero. If this happens, kill her and then go and talk to Captan Burd, who will express shock that she was a spy but give them permission to search her house and tell them to deal with any other spies as they please.
I delivered the Mysterium Xarxes to Martin, and told him that Mankar Camoran had escaped to Paradise with the Amulet of Kings. Martin believes the key to opening a portal to Camoran's Paradise lies within the pages of the Mysterium Xarxes, but he will need some time to study it, and ward himself against its evil power.
Steffan told me that the suspicious strangers have been seen on the road to Cloud Ruler Temple, usually near the runestone at dusk.
Captain Burd told me that no strangers were in town, although he said that Jearl had recently returned from a trip, I should talk to Jearl.
Jauffre was pleased that I eliminated the spies in Bruma, but is worried that the Mythic Dawn have already learned that Martin is at Cloud Ruler Temple. He promised to warn the Countess that Bruma is in grave danger.