Watching The Blacklist is akin to boarding a roller- coaster that stops, starts, needs repairing then jumps on to new tracks. Just when you thought you knew where you were heading, it throws up surprises. In tonight’s white- knuckle finale, you might be scrambling to keep up as certain characters’ demises slap you in the face. Red ( James Spader) sets a risky plan in motion, while Liz ( Megan Boone) confronts the biggest questions about her past. There aren’t many shows where you find yourself ardently cheering for the murderous criminal, but once you’re this deep in Red’s crazy world there’s no turning back.