Minecraft : the lost journals / Mur Lafferty.

Max and Alison are proof that differences don't stand in the way of friendship. Max is always on the lookout for a new adventure - even if it means getting into trouble - while Alison prefers to follow the rules. But both of them are fascinated by the beat-up old journal Max finds, and the strange gate its secretive author, the Enchanter, describes: a portal to an otherworldly realm of danger called the Nether. After they use the journal's instructions to craft the portal, Max and Alison squabble over whether to remain safe in the Overworld or journey into the Nether to find the Enchanter... until a fateful accident sends them through the portal. Trapped in a scary new world, Max and Alison find an ally in Freya, a fierce warrior who has been living in the Nether with her beloved wolf, Bunny Biter. With Freya's help, and with the clues that lie in the pages of the mysterious journal, Max and Alison embark on a quest to find the Enchanter, even as the Nether pushes their skills - and their friendship - to the limit.