George and Annie are off on another cosmic adventure to figure out why strange things are happening on Earth in the fourth book of the George’s Secret Key series from Stephen and Lucy Hawking. George and his best friend Annie haven’t had any space adventures for a while and they’re missing the excitement. But not for long, because seriously strange things have started happening. Banks are handing out free money, supermarkets aren’t able to charge for their products so people are getting free food, and aircrafts are refusing to fly. It looks like the world’s biggest and best computers have all been hacked. And no one knows why… It’s up to George and Annie to travel further into space than ever before in order to find out what—or who—is behind it. Stephen Hawking was a brilliant theoretical physicist and is generally considered to have been one of the world’s greatest thinkers. He held the position of Lucasian Professor of Mathematics at the University of Cambridge for thirty years and is the author of A Brief History of Time , which was an international bestseller. His other books for general readers include A Briefer History of Time , the essay collection Black Holes and Baby Universes , The Universe in a Nutshell , The Grand Design , and Black Holes: The BBC Reith Lectures , as well as the books in the George’s Secret Key series. He died in 2018. Lucy Hawking, Stephen Hawking’s daughter, is a journalist and novelist. She is the coauthor of the George’s Secret Key series for kids, as well as the author of the adult novels Jaded and Run for Your Life. She lives in Cambridge with her son. Garry Parsons is the award-winning illustrator of many books, including George’s Secret Key to the Universe , George’s Cosmic Treasure Hunt , George and the Big Bang , George and the Unbreakable Code , and George and the Blue Moon by Lucy and Stephen Hawking; Billy’s Bucket by Kes Gray; and What’s Cool About School by Kate Agnew. He lives in London. Visit him at GarryParsons.co.uk. George and the Unbreakable Code On another planet, the tree house would have been the ideal spot for stargazing. On a planet with no parents, for example, it would have been perfect. The tree house—halfway up the big apple tree in the middle of the vegetable patch—was the right height, location, and angle for a boy like George to spend all night staring up at the stars. But his mom and dad had other ideas, involving chores, homework, sleeping in beds, eating supper, or spending ‘family time’ with his little twin sisters, none of which were of any interest to George. All George wanted to do was take a picture of Saturn. Just one teeny photo of his favorite planet—the enormous frozen gas giant with its beautiful icy, dusty rings. But at this time of year, when the sun set so late, Saturn didn’t appear in the evening sky until it got dark out. Which was so far past George’s bedtime, there was no hope of his parents leaving him out in the tree house until then. Sitting with his legs dangling over the edge of the platform, George sighed and tried to calculate how many hours and days it would be before he was old enough to be free. . . . “?’S up?” His train of thought was broken as a slight figure dressed in long baggy camo shorts, a hoodie, and a baseball cap bounded onto the tree house platform. “YOLO!” George cheered up instantly. “Annie?” Annie was his best friend, and had been ever since she and her mom and dad had moved to Foxbridge a couple of years ago. She lived next door, but that wasn’t the only reason why they were friends. George just liked her: Annie, the daughter of a scientist, was fun and clever and cool and brave. Nothing was beyond her—no adventure could be shunned, no theory go untested, and no assumption stay unchallenged. “What are you doing?” she asked. “Nothing,” George muttered. “Just waiting.” “Waiting for what?” “For something to happen.” He sounded miserable. “Me too,” said Annie. “D’you think the universe has forgotten about us now that we’re not allowed to go on space adventures anymore?” George sighed. “D’you think we’ll ever get to fly in space again?” “Not right now,” said Annie. “Perhaps we’ve had all our fun already; now that we’re eleven, we’ve got to be really serious all the time.” George stood up, feeling the wooden planks rock slightly under his feet. He was almost sure that the tree house was safe and that there was very little chance they could both go crashing down to the hard ground below. He’d built it with his dad, Terence, out of stuff they’d scavenged from the local dump. And once, when they were busy constructing the “house” part where he and Annie now sat, his dad had plunged his foot through a rotten plank. Fortunately, he hadn’t fallen through entirely, but it had taken all George’s strength to pull him back up again, while below, on the ground, his twin sisters, Juno and Hera, shrieked with laughter. The good thing about the mini-acciden