Classicly

Two dwellers flew past him, male and female with arms linked, laughing soundlessly into each other's golden eyes. The male's great glowing wings brushed through Langdon's body. He stood briefly in a shower of whirling light-motes—and they didn't heed him, they didn't know he was there. They were only for each other, those two, and he was a ghost out of an unreal and unthinkably remote future.