SPOILER ALERT
If you’ve not yet read this book, you’ll want to stop now. But come on back when you finish!
Why did you write Evan Tredegar as a botanical pharmacologist?
During the Victorian era, British scientists embarked on expeditions to the farthest reaches of the globe, driven by an insatiable curiosity to uncover the unknown (to them). Among their destinations was the Amazon—a lush rainforest teeming with life. Home to a quarter of the world’s botanical species, this ecosystem held many plants and animals unfamiliar to European eyes. Many of these plants, though new to the explorers, had long been utilized by indigenous peoples for their medicinal properties.
How did the Amazonian blue frog step onto the stage?
Who among us hasn’t heard of the blue poison dart frog? Known for its brilliant color, this tiny frog’s skin contains potent toxins designed to drive off predators. Historically, indigenous hunters (carefully) used these poison dart frogs to their advantage by coating the tips of blow darts.
And in A TRACE OF COPPER a blue frog hitched a ride home among the plants Evan collected…
How did you build an invisible blue frog?
I began by researching how creatures like chameleons change color to blend into their environment… and ended up reading about dermal chromatophores. This cell type, located in skin, is similar to our own pigment-producing cells: melanocytes.
These chromatophore cells have finger-like projections that extend out among other cells. To darken an animal’s appearance, these cells move colored pigments out along these projections. To lighten, the pigments are pulled back toward the cell’s center.
Then I learned that chameleons use a subtype of chromatophore called iridophores. These cells are specialized to be reflective and/or iridescent by using a lattice of guanine nanocrystal.
Oof. That’s a lot.
Nanocrystals of guanine… If you’re thinking the word “guanine” sounds vaguely familiar, but you just can’t quite place it, that’s because I’m using it out of context. We usually hear about Guanine – G – as one of the four nucleotide bases used to construct DNA.
Don’t run away! We’re not going to talk any more DNA!
But that day I learned a really cool new thing. Turns out guanine crystals in scales are what give fish that flashing silver luster.
Silver. Mirror. Reflective. Disappearing into the environment. Invisible.
An idea of how to make a fictional frog disappear began to form. But I wanted this frog to bite people, to spread invisibility. For that, I needed an infection.
What looks like a bit like melanocytes, but is both infectious and curable? Amoebas! As they move around, parts of them extend finger-like projections called pseudopods.
Infections. Finger-like extensions. Reflective pigments controlled by the cells in a frog.
But while amoebas do infect humans, they are not known to do so intracellularly (inside the cell). Which meant the story needed an unknown intracellular parasite that could alter the workings of a human cell. And here our reality begins to blur into our fiction.
Enter Piyali Mukherji, doctor of infectious disease.
New Queen’s agent, Piyali arrives in a remote Welsh village and runs into her past love. Though emotions swirl, a young woman’s ankle is turning blue. What has infected her and can it be cured?
