Underground passage

There are many vaults I feel! And there are need the good equipment - lantern, food storage and Estonian dictionary (just for fortuity). There is a story about good Livonian knight Derrick von-Borengaupt. In the old times he worked out the underground passage from Narva to Ivangorod underneath the Narva river. He wanted to revenge an killing his wife and kidnapping his beloved son to evil Ivangorod's hijackers...