Ancient Tomb

At the end of round if there are characters in Ancient Tomb add 1 danger token to it. When danger level on Ancient Tomb reaches:
2 - draw 1 treachery card
3 - draw 2 treachery cards
4 - Ancient Tomb collapses - each character and enemy currently in Ancient Tomb dies and Ancient Tomb becomes closed location with
{2} Dig passage through Ancient Tomb, you can only move in this location.