The Sub Terra core box is required to play this expansion.

You didn't all survive!

With the help of a mysterious sponsor, you return to the caves in search of your missing companions. Engage the relentless Agent and equip yourself with items that will be invaluable in facing the many trials that await you underground. Darkness holds many dangers. Go prepared!

Investigation adds 15 new item cards that grant your cavers powerful abilities. Collect them from the cave floor or choose the Ruthless Agent who starts out fully equipped. Darkness hides many things. Be ready.