Doppelganger danger / Rebecca Caprara.

Enhanced descriptions from Syndetics:

Five middle schoolers' quest to save the multiverse continues in Rebecca Caprara's Doppelganger Danger , the explosive follow-up to Mission Multiverse , perfect for fans of the Percy Jackson series.



This action-packed sequel finds middle school band geeks Dev, Isaiah, Tessa, Maeve, and Lewis trapped in a parallel version of Earth as they fight to save their families--and the entire rest of the multiverse--from the villainous Empyrean One. Far from home and running out of options, it will take everything they have to get back to Earth and preserve humanity once and for all. The startling revelation that they are their own worst enemies forces a painful decision: Will they forsake the lives they once knew for an uncertain future?



This sweeping space adventure combines dry wit with a tension-laden plot to keep readers glued to the page.



"The warm rapport and slapstick humor the Cadets share is even stronger in this second series entry, as they've matured in their grasp of all things multiverse while maintaining an endearing commitment to middle school concerns." -- Kirkus Reviews