Journey to the Centre of Arcanum was the planned sequel for Arcanum. It was announced by Tim Cain in 2000 and was going to use Valve’s Source engine. However, because of disputes between Sierra and Valve, the project never advanced beyond its conception stages, and consequently little is known about it. Leonard Boyarsky said that [o]ur general idea was to try to do alot [sic] of the same things we tried to do with Bloodlines, but in the Arcanum setting. The title is based on Journey to the Centre of the Earth, a 1864 science-fiction novel by French author Jules Verne. Rather than making a sequel, they used the Source engine for their third project: Vampire the Masquerade: Bloodlines.
When Tim Cain was asked about the sequel, he replied, “The sequel was based loosely on Jules Verne's A Journey to the Center of the Earth, where we planned to continue the adventures of the great explorer Franklin Payne. He has disappeared into the bowels of the earth, and his wife has hired you to find him. We had laid out most the storyline, and it included finding prehistoric monsters, subterranean humanoids, and most thrilling of all, a clue about how magic and tech can be reconciled in the same artifact, something that most learned people had believed to be impossible. Of course, none of this came to be, but our talks about using the Source engine led to our making Vampire: Bloodlines.”