The dungeon starts out simple enough, its several rooms with monsters and creatures, it all seems innocent enough until they run into merfolk. The merfolk were guarding a treasure, but they tried to open the contents anyway. As they did, the treasure revealed itself to be a mimic (the paladin already knew this) and they struck it down before the mimic had a chance to inflict damage. They got a key, and progressed. Suddenly finding a room with a huge door, they insert the key and go through…And that was all that happened that session, no dying happened at all.