The Witcher 2: Assassins of Kings -
"Retrieve the Banner first. Exit out the small Old Gate. Ford the river, fight off the bandits and enter the ruins. Cross the first underground bridge, turn left and cross the next bridge to your left. Enter the tombs, go right and blast the wall out with Aard. You'l lmeet a ghost behind the wall. Tell him that you are of the Dun Banner. When he questions you, answer: 1. that he got it wrong, 2. that Coehorn commanded Nilfgaard, 3. that Coehoorn is dead, 4. that Vandergrift and Seitkirk commanded at Verden, and 5. that a priest led you to safety. They ghost will grant you the Banner and the Sword of the Dun Banner. Leave the Corporal's cap after you take these.