A realistic and truly rather frightening tale about a group students who are kidnapped on their way home from school (by a fake school bus driver who had killed the regular bus driver in cold blood in order to take his place at the wheel), when I read Lois Duncan's Five Were Missing in grade eight, I was actually a bit afraid of taking the school bus for a couple of weeks (not that I mentioned anything to my parents, as that would have likely resulted in them attempting to censor my reading choices, which was neither desirable nor even an option for me). And please note that when I claim that Five Were Missing is realistic, it was definitely this when it was first published in 1966, and when I read the book in the early 80s. Nowadays, it would more than likely be much more difficult for the kidnappers to have succeeded with actually hijacking a school bus, but in the 1960s and the early 1980s there really was no way for the kidnapped children to attempt to contact their parents when they realised that something was not quite comme il faut with regard to their trip home from school (as cell phones, iPads and the like were of course not as yet available).
Narrationally and thematically speaking, and for a rather short novel, Lois Duncan has in my opinion created not only a believable, at times rather massively intense and suspenseful plot-line, especially the five kidnapped teenagers are surprisingly nuanced and realistically conceptualised (and Five Were Missing is thus not simply a standardly mundane thriller, as seriously problematic issues, such as drunk driving, bullying and lasting physical challenges due to most likely a bout with polio are presented with both compassion and an appreciated lack of moralising judgment). Recommended for teenagers above the age of twelve or so (but with the necessary caveat that Five Were Missing indeed does paint a rather intense scenario, as it certainly frightened me as a teenaged reader).
Now finally, it appears that in 2012, Five Were Missing was republished and updated (I think under the title of Ransom) with references to cell phones, text messages and such, and if these references have simply been superimposed onto the original dialogue and scenarios without other textual and thematic changes (which is what often, if not what usually happens) I would strongly, no, I would actually very strongly suggest NOT reading the 2012 edition, and if interested read the original 1966 version instead (for while it is seemingly out of print, it is nevertheless still quite readily and cost effectively available used). And quite frankly, I do oh so much tend to vehemently DESPISE these types of "updates" and think they are generally both unnecessary and in many ways rather an almost unforgivable insult to today's children and teenagers (as though they could not appreciate a book written in the 60s, as though they could not and would not be aware of the fact that technology has indeed changed much since the 60s).