Faerie Wars by Herbie Brennan
As Faerie Wars, by Herbie Brennan, begins, the prince of a magical realm has escaped the palace in the dead of night. Someone is trying to kill him. Months pass, and, on the run from an encounter with Lord Hairstreak's men, Prince Pyrgus found himself running full-tilt down Seething Lane. A factory lay just ahead and once inside he slipped on a white lab coat and blended in with the rest of the workers.
He walked past the evil-smelling vats that churned out noxious Miracle Glue. He was surprised to see a birdcage hanging in such heat, and even more surprised to see it contained a mother cat quietly nursing her kittens. He found it strange that the Faeries of the Night kept pets. He asked an old man about it.
"Chuck in a live kitten and it makes a batch of glue stick better than anything on the market. 'course, that's a secret."
"You ... put kittens in the glue?"
"One a day," the old man said proudly. "There's one due to go in about now, so you can see it if you like. Mother cat's quiet now, but she howls for hours afterwards. Keeps calling the dead kitten, stupid little toad. It's a great laugh."
Pyrgus was horrified—and determined to do something about it.
Nearby but in another world, Henry Atherton was sitting down to a nice bowl of corn flakes. He had just finished a model of a pig that could really, truly fly. His mother seemed extremely vacant this morning. And then his father came in from spending the night in the spare room. Something was definitely wrong. His father refused breakfast, wouldn't kiss his mother goodbye, and raced off to meet the train. He grudgingly gave Henry a lift.
He didn’t want to talk to Henry, let alone answer his questions. No, indeed. So Henry had just blurted it out: "Are you having an affair with Anais, Dad?"
The silence was so deep it seemed to overcome the ticking of the car's engine. Henry sat quite still, his hand still on the door handle, looking at his father. He thought his dad would be angry, but instead he just looked distant, as if he was in the hot seat on Who Wants To Be a Millionaire? Are you having an affair with Anais? A. Yes. B. No. C. Not any more. D. We're just good friends. One of those answers is worth £64,000, Mr. Atherton. But the drop's a bit steep if you get it wrong.
When an attempt on Pyrgus' life brings him to Henry's world, the prince’s adventurous spirit has no regard for the humdrum rules we know. After all, why can't you break into a public school building if your father's life is at stake? Henry certainly has enough worries, but you can't let a friend down, now can you? Particularly if he's desperate to get home, and home lies in another part of the cosmos.
Fans of J.K. Rowling should try this series which is also British, quirky, and by turns dark and cheerful.