Summer vacation has just started and brother and sister Ned and Hazel Frump are looking forward to sleeping in, shooting hoops and all the other joys of summer but when their dad disappears, their summer plans change in The Mystery of the Martello Tower by Jennifer Lanthier. At first they assume that he is just off on a short business trip then when they see a photo of him in handcuffs being put in a Turkish jail it appears that this not one of his usual trips. Soon life for the pair becomes dangerous when they babysitter leaves town and their apartment is burgled. Safety comes in the form of some previously unknown relatives who take the kids in and help them solve not only their father's mysterious disappearance but some long unanswered questions about their family as well in this very exciting and suspenseful mystery.

For grades 5 through 8.