The Death Curse has struck, and ye merry band of adventurers have to unfuck it post haste. To do that, you're heading to the peninsula of Chult, a steaming green jungle hell full of monsters, dinosaurs, undead, diseases, inclement weather, potential heatstroke, and probably dysentery.
Lather on some bug repellent and don your best dungarees. I hope you like the smell of Fireball in the morning, because we're going to the fantasy equivalent of Vietnam.