Justice League #16

"It's a mystery in space: Why would the Guardians of the Universe hide top-secret intel deep in the bowels of a secret vault on Thanagar Prime? That's what Martian Manhunter, GL and Hawkgirl want to know! That's not the only puzzler popping off either, as an ancient connection that bonds Kendra and Shayera Hol unlocks the secret of the map on Hawkgirl's Dark Metal wings. Back on Earth, Starman and the Trinity look to create a wormhole that could transport them to Thanagar Prime. The only catch? It could vaporize them!"