Four years after announcing a hiatus, Trent Reznor and Nine Inch Nails have come back…smiling? There’s certainly a level of angst-y lament implied on the lead track from the forthcoming “Hesitation Marks” — the first NIN single since 2008 — but the bottom line is that “Came Back Haunted” is really five-and-a-half minutes of irresistible techno-funk. Layered synths and subtle industrial effects percolate atop a bouncy rhythm pattern until jagged guitar riffs explode from the mid-song instrumental break, which in turn leads to a sinewy, tribal vocal outro chanting the title over and over until the song’s abrupt conclusion. Acknowledging his absence, Reznor sings, “I said goodbye/But I had to try” — presumably referencing his adventures in film scoring and How to Destroy Angels during the interim. He also informs the listener, “I am not who I used to be,” but “Came Back Haunted” is unquestionably NIN, refreshed and ready to take no prisoners both in the club or the open festival field.