In the future we’ll have to explain to our grandchildren that Justin Timberlake and Britney Spears were once a couple. Then we’ll have to explain who Britney Spears was. This rebuke of a cheating lover marked the end of Timberlake’s Britney phase and his coming out as a real singer. His voice is under control, even in falsetto, while funereal voices and organs and driving rainstorms fill in the furious Timbaland-produced backing track.