“Let's give Imagine Dragons credit where it's due. On their multiplatinum 2012 debut, Night Visions, the Las Vegas act found a way to reheat old-fashioned arena-rock catharsis for the segmented pop world of the 2010s — fusing Coldplay's heart-hugging balladry, Arcade Fire's darkly heroic surge, neon Killers synths and elements of hip-hop, folk and EDM into something new. Their biggest hit, "Radioac”