The Long-Lost Map — P.C. Baccalario

Jason, Julia, and Rick have crossed through the Door to Time into ancient Egypt, a land of labyrinths, riddles, and secrets. But when the passageway collapses around them, Julia ends up back at home, in the present -- with the door shut tight behind her.

Now the boys are trapped in the past, and there's just one way to get back to Argo Manor. They must find the long-lost map of Kilmore Cove hidden somewhere in Egypt's Land of Punt. And to do so, they'll have to solve more puzzles left by the enigmatic Ulysses Moore.

But before long, Rick and Jason realize that they are not the only travelers from the present in search of the mysterious map. Can they be the first to find it?