“Funny, a vampire with SAD,” I quip.

The tall Ukrainian peers through mirrored goggles. “Intolerance to sunlight does not qualify me as vampire.” Leonid is our grower. It doesn’t matter how clever the plant biologists are, myself newly included, if you don’t have someone with green fingers to nurture your gene-hack creations. And Leonid is, everyone says, the greenest of the green.

“And SAD?”

He pauses, secateurs in hand. His own pair, never lent, scrupulously cleaned and sharpened. “Is not funny.” He glances at my sandals, feet and ankles lobster red. “Being underground is no hardship, for me. Grow lamps are gentler than sun.”

The first hack we do knocks out a plant’s defences against direct sunlight, as well as their diurnal response. They don’t need them and grow ten times faster in the vast subterranean hydroponic fields, where artificial lights always shine benignly, powered by another equally vast field far above our heads: solar panels spanning the arid desert landscape .

“Grow lamps have plenty of blue, and vitamin D supplements help.” He shrugs. I’m only half listening, wondering when it will be cool enough to escape up top again. “As does regular sleep, avoid alcohol, see best in others.”

I ignore the barb, if barb it was. “And these?” I gesture to the leggy yellow flowers he grows in this small corner of the complex. If he wasn’t so damned talented, would we indulge him?

“These?” Sunflowers reflect in twin lenses, a constellation of otherworldly stars. “These I grow for my soul.”