zero and 2?

[john doe]

Why are there 2 versions on steam of part 2 and the prequel zero? i want to know before i buy this whole game i dont want to buy things twice so what's the diffrences between the 2 versions of both games? and should i buy both versions of the games?

[Soulthorn]

They are the same novels, but one set are standalone programs, while the others are part of a DLC (downloadable content) that you start from the Invisible Apartment application as chapters.