There are rings on the ground. Spears will rise from them but the trap is not fast. Just do not stand on the rings.
When you click the machine in the middle the spikes rise. Knock mobs out to the wall, then run to the middle and click the machine. Works very well for the troll. After all are dead activate the 2 stones to open 2 more doors with 2 more stones. This opens a fifth door with a minotaur. Kill him and proceed up the stairs to the portal.
A Treasure Chest is behind the barrels near one of the Protection Stones.
The Blessed Stone: Contaminated Elena is easy to defeat... too easy. When you drop the last of the other mobs she rises as Darkscream! IF you have completed Where's Goblynn Now?, Old Hobbus and his poochum will arrive, assist you with the fight, and sacrifice themselves at the end to make sure Elena pays for her crimes.
Get Darkscream to chase you across the spikes as you can trigger them and catch her with them. She will rise up and then dive into the ground, arising in a fearsome series of attacks. Just stay away when you see her rise. OR... smack her with a special attack when she rises to put her back on the ground, then continue wailing on her.