Skyland: Heart of the Mountain Collector's Edition

In an outlandish world, humans abandoned the ground's toxic soil and settled on the shoulders of sleeping giants. Life essences of these colossal relics proved to be an inexhaustible source of energy that allowed the entire civilization to form. The crew of aircraft Nightingale was sent to investigate a penal colony settlement in the clouds. While investigating the horrible conditions of the inmates, they find themselves uncovering a plot that threatens the entire world! Can you uncover what's behind the conspiracy in time?