Unspeakable Box contains all Kickstarter exclusive stretch goals for Cthulhu: Death May Die unlocked during the campaign. It includes:

5 plastic dashboard trays
18 Investigators miniatures and boards
DAGON elder one box (4 minis, 13 cards, 15 tokens)
YOG-SOTHOTH elder one box
LOST EPISODE 1 box (3 minis, 25 cards, 10 tokens)
LOST EPISODE 2 box (4 minis, 25 cards, 10 tokens)
LOST EPISODE 3 box (28 cards, 8 tokens)