Kayo! The Brixton Brothers: It Happened on a Train by Mac Barnett

"I'm a retired detective, okay?"

Dana rubbed his chin. "So what's the plan? I mean, there's nothing we can do, right?"

"Look," said Steve. "There's an innocent person who is almost definitely in some kind of danger right now. What I'm saying is that I've been trying to stay out of the game--"

"The game?"

"Yes, I've been turning down jobs left and right. But I can't let this happen. This girl needs a detective. I'm reopening the Brixton Brothers Detective Agency. Dana, we're back in business."

"WE?"

Steve Brixton thinks he has given up the gumshoe game and retired to taking out the trash, until he boards a train for a social studies convention with his friend (Don't call me chum!) Dana. A fan and imitator of the Bailey Brothers books, Steve is fond of dime-novel detective lingo and feels a case coming on as soon as he boards the train, despite its lack of Orient Express elegance. What about that sealed, windowless car at the end of the train? There's got to be a mystery there somewhere.

And when he meets an intriguing girl on the dining car of the train, his detective DNA begins to assert itself. Claire is not your standard pre-teen queen, but there's a certain attraction there, an air of mystery, and when Steve looks for her to return the book she left behind in the dining car, all his sleuthing skills come to the fore when she is nowhere to be found on the train. Steve is sure she has been kidnapped and can only be being held prisoner in that mysteriously sealed car at the end of the train.

With a very unenthusiastic Dana reluctantly playing gumshoe sidekick, the two seventh-grade sleuths are off and detecting as they find themselves in the middle of a stolen antique car case that soon finds Steve locked inside a broiling sauna, shut inside a car trunk, cuffed, locked, and left in a closet with Claire and Dana, and with his chums, escaping just in time from an exploding warehouse full of antique cars in Mexico.

It's all in a day's sleuthing for the reprised Brixton Brothers Agency as Steve bum-rushes, kayos, and wooden-horse-capers on his way to the closing of the case in Mac Barnett's latest installment, It Happened on a Train (Brixton Brothers) (Simon & Schuster, 2011), soon available in a brand-new paperback edition. A deliciously tongue-in-cheek parody of the venerable Hardy Boys and Nancy Drew teen-sleuth genre, this one offers page-turning adventures and literary satire along with its many laughs. Kirkus kayos their review, saying "Barnett’s sly and often silly Hardy Boy parody chugs along with plenty of laughs and enough honest-to-gosh mystery to please any lover of boy detective fiction. [Adam] Rex’s black-and-white pencil drawings (which also parody the Hardy tales) are still a fine match for the goofiness."

Earlier entries in this series include The Ghostwriter Secret (Brixton Brothers) and The Case of the Case of Mistaken Identity (Brixton Brothers), with a brand-new installment, Danger Goes Berserk (Brixton Brothers) published October 12.