As far as I’m aware, there is no volume 2 #1 – this is a direct continuation from the previous Secret Voice issue, likely just called volume 2 as it jumped from Adhouse Books to Study Group’s own publishing imprint.
Interestingly, the further away we moved from the cool looking guy on the book’s covers – Doctor Galapagos – the more gripping The Secret Voice became, as Zack spun out a world around his Red College colleagues of doctors and wizards and the evil, conquering Smog Emperor they’re trying to best. We definitely check in with Galapagos in these two issues, but we get a lot of face time just bouncing around the kingdom, to the good and the bad, and SV moves beyond what was questionably quirky in issue one for some deep fantasy goodness. The extras in these two issues – one definitely connected, and a (to be continued) two-parter that may not be connected, but who knows – further enriches that sense of world-growing and building. I’d even offer that the cheap paper quality and variation-on-a-tone coloring style gives the books the proper, back-of-the-bin pulp vibe; done up with a professional sheen, you might lose that sense of discovering something fresh and fun.
This was later collected into a single trade. The excitement of these two issues is renewed therein, but however you read it, I hope the promise of more Secret Voice to come is fulfilled.