DON'T MISS: "Riverdale" - This one could either be really fun - or a complete disaster. Archie, Betty, Veronica, Jughead and the whole comic book gang show up in this subversive live-action drama. But you may not recognize them. It's a radically different take on the wholesome town, which turns out to be rife with danger and dark secrets. One of those secrets involves our beloved redhead (KJ Apa) having an affair with his teacher, Miss Grundy. Yikes. 9 p.m. Thursday, The CW.