unheard

"The singular workload at this scale is unheard of," says Mr Bizo, "it's such an extreme engineering challenge, it's like the Apollo programme."

Though recruits from abroad in the Russian army are not unheard of, this is a rare case of a captive foreigner speaking on video.

"He seems to break every record going. It's unheard of what he's doing. What an unbelievable player," said Foden.

Storms across Southern California in September are unusual, but not unheard of, Thompson said.

And in a world where 10-year waits for sequels are not unheard of, six for Borderlands 4 doesn't seem like such a bad deal.