"And us," says the young wife, tugging up the arm of her husband. His name is Joshua. Neither Frank nor Ivy can remember hers.

The beam-up point takes them to a white door — "Zoo of the Peculiar and Protected" — and Moran, their swarthy tour guide. He turns a wheel lock and gesticulates over the threshold.

"Welcome," he says, "to the tour that will extend your reality."

Frank and Ivy squeal and squeeze each other with gleeful grins. They might be the oldest in the group but they are also the most enthusiastic. When the door turns to a lock behind them, they squeal at that too.

A boardwalk tracks in a loop with metal-barred enclosures on the right, white doors studded along the left. The boardwalk's centre section is a screen of lush greenery and butterflies whose wings extend farther across than Frank's handspans.

"Only two of the zoo's doors are locked," their guide explains. "The entrance, which you just walked through, and the door to our newest beast, The Unknown."

He pauses to soak up the oohs and aahs.

The new wife raises her hand and says something low.

"Why aren't the other doors locked?" Moran asks.

"Good question, Erin."

Ivy nudges Frank with her elbow. Erin, she mouths, and he nods.

"Our creatures dare not leave their enclosures, thanks to Aaru, our Chief Scientist who also happens to be an honest-to-Jupiter shaman. His rituals keep the creatures calm and us safe. We'll meet up with him at some stage.

"But we begin," he continues, "with the Reconstructs. These are live creatures, folks, fabricated by splicing the genes of existing species. They have little genetic relationship to the original animals but have been created to match historic accounts."

The group gasps at the sight of a tiger, a platypus, a dodo.

"Next up, endangered species. We're part of a breeding program that supplies the Star Alliance with rare species for repopulation."

The boardwalk auto-extends with the group's movement. Ivy's eyes widen. There must be more than fifty creatures in these confines.

Moran awaits the group at the pygmy sloth enclosure.

"Now to the final section, where we house our creatures under study. If it's brand new to Earth, we have it first." He puffs out his chest. "These creatures are not fully understood. Stay on the inside of the boardwalk if you would. Yes, towards the butterflies, Erin. And you will find our latest and most terrifying acquisition in the last room."

At this, Moran stops. The entire tour group is unbreathing.

"The last rooms holds a grotesque monster known universally for its wiles and ferocity," he says. "The Unknown."

The crowd ripples with escalating murmurs, and they round the bend in a gathering swarm.

Frank and Ivy lag behind to take in the curiosities at a more leisurely pace, but their peaceful meander is disturbed by screeches of delighted terror.

"Did you see that? How horrific!"

"I know! Was it feeding?"

"Black! Pure black."

"Blacker than the Devil himself."