A Light In The Dark is a quest of Necropolis playthrough in Might & Magic: Heroes Online.
Since there is no communication on the island, Artak asks of the hero to go atop the tower and lit the fire. On the top, the hero has to fight the raging prisoners. To do so, the barricades must be destroyed and at least one stack of orc captives have to be slayed. Once done, the signaller will activate the signal, a green flame.