An additional map for use at the Gate menu titled:

“The Beginning of The End” - An additional Map +5 missions. Moderate difficulty.
“The Emissary from the Netherworld” - 5 additional missions. Moderate difficulty.
“Price of Blood” - 5 additional missions. Hard difficulty.
“Runaway Cause and Effect” - 5 additional missions. Expert difficulty.
“Prelude to the Destruction.” - 5 additional missions. Expert difficulty.

Good luck out there!