Elesa and the Battle of the Seeds - Marie Armano

Elesa thinks she's about to spend a quiet summer with her Grandma in her Paris flat, until her Grandma disappears. When a strange man turns up at the door requesting a box Elesa has never seen, she embarks on an adventure that take her all the way to the Bunker of the Apocalypse on the remote Island of Svalbard. With the help of her newfound friend Achilles, Elesa will have to swallow her fears to find her Grandma and face a menace much bigger than her.