Several H.A.M. guards are found in the lower level storeroom of the H.A.M. Hideout through a hidden trapdoor during Death to the Dorgeshuun. Zanik will knock out the guards using a crossbow as the room is traversed. After listening in on the secret meeting a guard will appear, and you will be knocked out and transported to the H.A.M. jail cell.
Three H.A.M. guards appear during the final boss fight of Death to the Dorgeshuun. They appear in the Watermill cellar. They need to be killed before you can attack Sigmund.