The main character here who goes by the name 'Humbert Humbert' a sexual predator who is also the book’s narrator of what appears to be a memoir or confession has an obsession for young girls or ("nymphets" as he calls them) 

He comes to the United States after inheriting a business and separating from his wife, Valeria.

He rents a room from a widow called Charlotte Haze and he becomes sexually obsessed with her 12 year old daughter whom he calls 'Lolita'. He marries Mrs. Haze to be near Lolita, and when the mother is killed, he takes the girl on a trip across the United States.

Many books and movies portray monsters, but this book puts us in the mind of a monster and raises uncomfortable questions.

It's very well-written and explores themes of love and conscience and it challenges the way we think about human beings and the nature of evil.

This has been one that's been on my to-read list for many years because I love classics and this one is always high up on the best books of all time lists; I'm glad I finally read it. It's a very good piece of literature.