Nicola writes: Lucius III is a sequel which I never thought we would get.
The first game in the series was almost a recreation of the Omen movie, where Lucius had just discovered hes the son of the devil and must kill everyone in his household without getting caught. The second game followed on and had us begin our adventure within a hospital which we were placed into after all of the horrific accidents which occurred at our home. The third game also takes place immediately after the conclusion of the second game.
So, as far as a trilogy goes, everything all seamlessly binds together, yet the gameplay style seems to change as we jump from one to another.
Source: N4G PC Lucius III [3] (PC) Review | GamePitt