Redeye flights are one thing. Redeye jobs are another.

Dozens of men and women who help keep Pittsburgh International Airport clean and shiny report for work at 10 p.m. every night to give the terminals a good scrubbing.

That luminous shine that makes Clayton Merrell’s “The Sky Beneath Our Feet” terrazzo floor in the Airside Terminal glitter each day? That’s due to the hard work of the staff of ISS Services, the company contracted for cleaning services.

“Most rewarding part is in the morning, once we get finished,” says night manager Oshea Vereen. “We have employees that take pride in their jobs and without them, there is no clean airport.”

Take a look at what goes into making an international airport look pretty every single day.