Collard, Sneed B. Double Eagle.
Mike has to spend the summer of 1973 with his father who is working at a marine biology lab on the coast of Florida. It's very different from his routine life in California, but he quickly settles in and makes friends with Kyle, whose father is also working at the remote location. Both boys have an interest in collecting coins, and are intrigued by the recent explorations of a nearby sunken ship. When they are poking around the old fort in the area, Mike turns up a gold double eagle coin, which would be worth a lot of money if it authentic. The boys research the matter (at a library and coin shop-- remember, this is 1973!) and are motivated to find out exactly what is on the sunken ship when an elderly resident gives them a journal that dates back to when the ship went down. A hurricane is on its way, however, and the boys must do some fast sleuthing before the storm hits.
I didn't think I would like this book at first, given the historical topics as well as the 1973 setting, but it was a breezy delight. Mike and Kyle's friendship rang true, their exploits kept the lot moving along, and the bits of intrigue that crop up left me wanting to know more. I also liked that Mike, who is 14, appreciated one of the young woman student's bikini wearing-- but also disapproved of two other young men who appreciated the same woman in an inappropriate way. After having read Only the Good Spy Young and Cammie's descriptions of Zach's attributes, it was great to read a similar experience from a boy's perspective, and one that was tastefully done. The 1973 setting was described well enough to place the story in that time, but not with too much detail to bog things down. Mysteries are certainly something my students have been craving, so I'll be adding this one.
And trying to read all of The Prince of Mist, since commenters mentioned it was super scary. (But I'll try to read it quickly, Wendy!)
Park, Linda Sue. Storm Warning (The 39 Clues, Book 9)
These books make me wish that I could follow clue oriented mysteries! I'm sure that students who have this ability have been checking out the web site and gathering more information. I am just happy to read the stories and marvel at how seamlessly the different authors work together.
Amy and Dan head off to the Bahamas with Nellie to find more clues, but start to get suspicious of their au pair. It turns out that she is telling all of their whereabouts to McIntyre in order to keep them safe. Amy and Dan aren't sure what to do-- they don't trust her as much, but need her help. After retrieving a clue in the Bahamas, they head off to Jamaica, where they meet a librarian who was educated by the beneficence of their grandmother. Lester also has a box that is essential to finding out more clues. The Kabras make a brief appearance, and more light is shed on the different branches of the family. One of my students has the 10th (and last) book, so maybe I'll be able to borrow it to see how everything ends! These are good action adventure books even for people like me who don't take the time to figure out the clues.
Picked up Darren Shan's Procession of the Dead, which was published in Europe in 1999-- it is in the adult collection of my public library and really is not meant for middle grades. I also took a look at Tara Kelly's Harmonic Feedback, about Drea, a girl who is interested in music and is trying to deal with her Asperger's Syndrome, but it also included details that made this more suitable to high school reading.