This is the first book in a brand new series by Rick Riordan (of the Olympian series fame). When their father disappears in front of them in a mysterious and obviously supernatural incident at the British Museum in London, estranged siblings Carter (14) and Sadie (12) start on a trek to rescue him. Luckily, as direct descendents of ancient Egyptian royalty, they discover they have a few powers of their own to help them in their efforts. This struck close to home for me as I realized that in order to rescue their dad, the kids have to stop a horrendous evil trying to take over the world from within Camelback Mountain in my own Phoenix, Arizona (eek!). Truly an enjoyable read and I especially enjoyed lording it over my nephew as I got to read it first while he languished in agony in the background ;-)
This is rated PG due to some action sequences but stays right in line with the level of writing and action as in the Olympian series.