If you guys are in the mood to read some really creepy and unexplained disappearances, I suggest you pick up a copy of either one of these books.The books chronicle children, adults and the elderly who disappeared, sometimes in the presence of friends and relatives.
The disappearances are so unusual in some cases. Kids, the elderely, the disabled disappear into thin air without any traces. There are some cases in which the missing individual will turn up weeks later without any memory or even a scratch on them.
A lot of the cases have some unusual common factors. The strange missing cases will definietly send a shiver down your spine. One of the creepiest true books I have ever read.
EDIT: There are actually more books in the series. North America & Beyond and Devils in the Details.