Depending on how quick Underworlds goes and how late people want to stay, I have another new toy to try.
https://www.shutupandsitdown.com/videos ... -whispers/Three to four players, Game of Thrones style shifting cubes around conquering a map, but with the twist that you don't actually control any one of the factions on the board but are a secret society taking positions on all sides, trying to manipulate the end game faction score order to match your hidden plans. Plans which you can change part way through the game.
Nice simple rules and is meant to play pretty quick (around 90 min).