Two years ago, Underworld duo Karl Hyde and Rick Smith had an epiphany. After more than three decades of working together — through some unremittingly lean early years; an epoch-defining, mega-selling turn in the 1990s; soundtracking the London Olympics opening ceremony, and a fractured and increasingly separate recent past — the pair suddenly realized a convenient truth. In touring their groundbreaking 1994 album "Dubnobasswithmyheadman," a record that shifted the parameters of what was possible in dance music, the two men figured out that not only did they appreciate each other, they also liked each other.

"It had to happen eventually," Hyde, the band's engaging frontman, tells me when I meet him one Friday afternoon in a hip central London bar. "And there are lots of things that have contributed to it. But the bass line is that after such a long time we have found this undiscovered connection, a symbiotic relationship that's been made clear to us. We're very different to one and another and we both cover areas that the other can't or doesn't want to or hates or whatever. But we've realized that is a strength."

It took a creative absence after 2010's "Barking" — Hyde released two albums with Brian Eno as well as a solo effort: Smith worked with film director Dany Boyle — to draw that conclusion.