Grave of Robin Hood

A secret treasure buried inside Robin Hood's grave . . .
Maddie Jones accidentally blew up her dad's museum. Now the place is going to close its doors. Forever. Sifting through the ashes, Maddie finds a mysterious iron box with a map inside dating to the fourteenth-century. The map alludes to the grave of Robin Hood and a vast treasure . . . riches from the Crusades that could save the destroyed museum.
But when the treasure map falls into the hands of an old hag who might be the immortal Sheriff of Nottingham, Maddie and her brothers must race across England to reach the treasure first. Throw in a secret sect of masked archers determined to keep Robin Hood's grave buried forever, and the Jones siblings are in for a historic ride.
Rob from the rich and give to the poor? Nah, better to rob from the dead and keep the riches for yourself.
Maddie Jones is an edgy Nancy Drew meets the Goonies with a voice like Percy Jackson.