The cross country trip is exciting and effectively done. I liked seeing that Kate had taken her training and used it to leave notes for the brothers. Alex's presence lends a bit of extra threat to the whole proceeding, since he definitely seems half a bubble off. Since Lawrence is an entire bubble off, his actions seem reasonable!
Above combines elements of survival, conspiracy, and adventure novels in a compelling way. Readers who like Smith's other work, such as Peak or the Cryptid Hunters books will certainly want to pick up this series, which will also be popular with readers of Horowitz's Alex Rider books, Klavan's The Last Thing I Remember, and Dashner's Eye of Minds series.