At the start of Shivering Isles—the latest expansion for Elder Scrolls IV: Oblivion —the madness only runs skin-deep. You come into the Shivering Isles as a would-be champion, recruited by the demon that runs the place: the "Lord Of Madness," who's shaped his realm after his own split personality. One half, Mania, bursts with wild foliage and brightly colored monsters, while the other half, Dementia, drags you through grim mud and bogs. And most of what you'll do here is weird, nonsensical, and even evil. You'll suffer drug withdrawal, help a peasant with his suicide pact, and torture suspects based on nothing but a hunch. The locals' neuroses start to become your own, and usually you have no choice but to follow them—or just walk away.
The idea that a game could disorient you into doing things that seem like nonsense is incredibly tantalizing, and it makes Shivering Isles smarter and trickier than the original Oblivion. And while it's easy to blow through the main quest and walk out a legend, Shivering Isles offers plenty of disturbing moments, especially if you like to play as a good guy. Luckily for your reputation, Oblivion takes a laissez faire attitude about everything that happens on the Isles—but that actually makes the experience feel less immersive. Whether you feel like a tourist or an inmate is entirely up to you.
Beyond the game: Bethesda has announced this will be the final Oblivion expansion—but who knows, maybe they'll ship some more of that overpriced horse armor.
Worth playing for: Everything in the Isles seems wilder and more imaginative than the knights-and-castles world of Oblivion, from a sword that changes at dawn and dusk to the will-o'-the-wisps that float by the paths and the fiery, purple-streaked night sky.
Frustration sets in when: The "madness" jokes in the dialogue can go too far: the Lord Of Madness is too cute by half, and some of the townspeople suffer from high-school drama-club smarminess. You'll even run into pop-culture puns. (Those crazy "gnarls" have "bark," guffaw.)
Final judgment: More of the same, but weird, wicked—and psychotically pretty.