Everyone knows the story, or at least they think they do. But as is the case with much classic literature that enters into popular consciousness, much gets lost or forgotten or shockingly misremembered (I'm looking at you, Wuthering Heights, and your freakish misinterpretation as a love story!) Stevenson's tale is both more and less than you probably recall it being, far more reliant on frames within frames in a way that makes you wonder if he wasn't a long-lost Bronte sister and with much less overt in its depictions of evil.
There are many theories regarding the latter and the possible implications Stevenson's apparent timidity: that he was eliding obvious references to homosexuality, or possibly child prostitution, a major scandal over which happened during the time he was writing. I personally think Stevenson left Hyde's perversions deliberately opaque as a way of demonstrating the duality of nature even in his reader, for each of us supplies from some dark corner of our being suggestions as to what the infamous Hyde could have been up to, suggestions all the more disturbing for coming solely within ourselves.
This particular edition includes several other tales that further illustrate Stevenson's fascination with duality and evil, as well as an essay, "A Gossip on Romance" that should be required reading for anyone enrolled in a creative writing MFA program. Rather than seeming extraneous, the extras add to the enjoyment of Stevenson's classic, as does the excellent introduction by Luckhurst, which makes getting to know this particular tale all over again an utter delight.