While explosively stripping the evil pirate LeChuck of his demonic mojo, Guybrush Threepwood inadvertently infects the entire Caribbean with the arch-fiend's expelled voodoo, which threatens to transform buccaneers into unruly pirate monsters.
Don't listen to the people who keep mentioning it "isn't like the original games". Well duh, it's a new game from a new company in a new decade; get over it.
I think Telltale's unique gameplay style fits very well with the Monkey Island series, giving it plenty of room for tons of silly dialogue, freedom to expore, and the ability to take nearly everything that isn't nailed down and put it in your awesome coat. I thought it had a very respectable balance between making it feel like an old-school Monkey Island game but also leaving room for it to stand out as something new.
As for those who keep downvoting it just because it isn't the originals, then go play the original game. It isn't going anywhere!