The World Between Blinks by Ryan Graudin and Amie Kaufman
Discover a magical world where lost things are found … Whenever cousins Jake and Marisol get together, adventure follows. They have their late Nana to thank for that. Her epic trips and treasure hunts were the stuff of family legend. This summer, with the whole family reuniting for one last vacation at Nana’s home, the cousins are in for a legendary trip of their own.
Following a map Nana left behind, Jake and Marisol sneak out to a nearby lighthouse – then accidentally slip into another world … The World Between Blinks is a magical place, where all kinds of lost things (and people!) end up. Everywhere they turn, the cousins find real mysteries from history – plus a few they thought were only myths.
But the man who holds the key to Jake and Marisol’s journey home doesn’t want to be found … and if the cousins don’t catch him fast, they could end up lost in this world forever.