What is the most disturbing or shocking book you have read?
For me, Iain Banks 'The Wasp Factory' would definitely be near the top of my list. It is hard to discuss the plot without giving too much away, nevertheless, the novel is written from a first-person perspective, told by 16-year-old Francis Cauldhame ("Frank"), describing his childhood and all that remains of it. Frank hates women, and misogyny is a major theme throughout.
The "Wasp Factory" that the title refers to is a mechanism put together by Frank, made from a huge clock face, salvaged from the local dump, encased in a glass box. Behind each of the 12 numerals on the clock face is a trap which leads to a different ritual death (for example burning, crushing, or drowning in Frank's urine) for the wasp that Frank puts into it via the hole at the centre of the clock face. Frank believes the death "chosen" by the wasp predicts something about the future.
Warning this is not a spoiler! More brutal murders of animals occur in the novel, frank even describes the killings of his younger brother Paul, his cousin Esmerelda, and another boy, Blythe, as simply a phase he was going through. As these three deaths are no surprise you probably cannot imagine what other twist and surprises occur.
I would definitely recommend this book as although it is disturbing, I wouldn't deem it as scary. It is also the first the first novel by Scottish writer Iain Banks, which following its success allowed him to write full-time.