Not my field of expertise to be honest so treat the following as just an opinion. Both are small niche RPG publications but they both occupy the same space. It may be more of a 'confusion over product' type consideration here.
This was the main reason I didn't name one of my projects 'Pitchforks and Torches' (as opposed to Pitchforks and Witches) as there was already a product called Torches & Pitchforks and another called Pitchforks & Torches.
Personally (and feel free to ignore this) I would probably rename it to avoid confusion (and you can amend Into the Unknown to something similar.. Journey to the Unknown (this was an old film) or something like that).