This is book number 3 in the Mighty Jack series.
It's the middle-grade team-up of the century as the heroes of New York Times bestselling author Ben Hatke join forces to save the world in Mighty Jack and Zita the Spacegirl.
Jack and Lilly are no strangers to heroics. They’ve befriended dragons, battled giants, and even earned the loyalty of a goblin army. So when they meet Zita the Spacegirl, fresh from her interplanetary travels and seeking their help to face a new threat, they’re more than ready for another adventure.
But the danger growing just outside the door to their world is greater than anything the new friends could have imagined. An army of giants and screeds stands ready to lay siege to Earth, determined to put the age of humans to an end.
With the gate between worlds growing weaker and time running out, can the heroes come together to save their world from their greatest enemy yet?
"Hatke's latest adventure is a wonderful and exciting page-turner, seamlessly blending dragons, giants, robots, and portals to other worlds, creating instant appeal for almost any young fan of graphic novels, fantasy, fairy tales, or science fiction...Perfection." —Kirkus, starred review
"Retaining the humor, daring exploits, and dynamic cartooning of Hatke’s previous books, the crossover is enjoyable and satisfying, if at times a tad predictable, and could serve as either a solid epilogue to both series or as the start of a new chapter in a larger shared universe." —Publishers Weekly
"Hatke offers up a hit parade of characters both human and otherwise, with plenty of fearsome creatures in his classic style." —Booklist
"Readers can hope this is the beginning of many adventures with this crew, but if it turns out to be the end of both series, well, it’s an utterly satisfying one." —The Bulletin of the Center for Children's Books
"Jack and Zita make a stunning team in this high-stakes adventure—a must for fans of both series." —The School Library Journal