Alien
I saw a clip of Alien on TV the other day and it reminded me of the very first time one line of copy stopped me in my tracks. My parents have this book (this isn't my picture), and one day, sitting in the chair next to the bookshelves, I randomly pulled it out to look at it. I must have been about 7 or 8. The picture didn't make much of an impact, the title must have been appealing enough to make me pull it out, but what really terrified me, and I mean turn-your-stomach-keep-you-up-at-night terrified, was the single sentence 'In space no one can hear you scream'.
For reasons I can't remember, I thought this was the single most horrifying thing I'd ever read, or could possibly ever imagine. Perhaps it was around the same time I was trying not to make myself go mad by thinking about the edge of space, but it shook me to my 7 year old core. Suddenly, the egg on the cover because a menacing pod, full of...who knows. All I knew was it'd make me scream and if I was in space, no one would hear me which would mean I'd die because no one could come and rescue me. I tell you; it gave me nightmares.
Anyway, I thought it was a fantastic example of the effect 28 little letters can do. At least, to a 7 year old girl.