Henry was a novice in the Dungeon raiding game but if everyone was so convinced it was a money-making venture, he had wondered how just the flashy things in the wall could possibly be what the entire ordeal had been about.
It just seemed… incomplete.
And then, while Eloise was reproaching Norbert for greedily seeking the best loot for himself, Henry had looked at the Throne. The seat the Lich never left. Not even when Henry had opened the contraption and gotten his hand around the Phylactery.
With a closer look at the Throne and his perception to guide him, he noticed the part that had been damaged by Louis' spell revealed something behind and he had a moment of inspiration that the Lich had another hiding spot almost as important to it as the Contraption on the ceiling.