Up Close: Susan Spann

A Novel That Immerses

By Steve P. Vincent

There’s something very special about a novel that’s steeped in so much detailed historical research that it feels completely real. Easier now than ever thanks to technology, desktop research gets authors some of the way to where they need to go. But when an author achieves total immersion in a culture, the results are spectacular.

TRIAL ON MOUNT KOYA by Susan Spann is one such book. The sixth Hiro Hattori novel, it sings with Spann’s deep love and knowledge of Japan. I sat down with Spann to discuss the novel, some of the research she undertook to write it, and the amazing coincidence that will help her celebrate the book’s release in style.

Can you tell us a little bit about TRIAL ON MOUNT KOYA and your heroes—Master ninja Hiro Hattori and Father Mateo?

TRIAL ON MOUNT KOYA is my dual love letter to Agatha Christie’s And Then There Were None and the sacred mountains of Japan. Hiro and Father Mateo climb to the summit of Koyasan, carrying an urgent message for a ninja spy posing as a priest on the sacred mountain.

When a snow storm traps them on the mountain, and a killer begins murdering priests and posing their bodies as the Buddhist judges of the afterlife, Hiro and Father Mateo must stop the killer before he adds them to his grisly council of the dead.


Although this book is the sixth in the Hiro Hattori series, each novel is written to stand alone, so new readers will feel just at home in Hiro and Father Mateo’s world as those who have read the series from the beginning.

Tell our readers why they’ll love this novel. What about it will keep them up and flicking pages through the night?

Murder victims posed as Buddhas, a killer who strikes without warning, and a temple filled with priests who are not all what they claim to be . . .

Fans of classic mysteries will love the “locked room” feel and the suspense of tracking a killer who chooses his victims for their similarity to the Buddhist “kings of hell.” The twisting, fast-paced plot combines a traditional mystery with the rich details of 16^th century Japan.  

You’re a historian, same as me. Can you give our readers some insight into the research you did for this novel? 

In addition to book research (which I love), I traveled to Mount Koya twice, where I stayed in thousand-year-old temples, talked with Shingon priests, and attended worship services—including the famous goma, or fire ceremony, which plays a role in the book. Koyasan is the beating heart of Shingon Buddhism in Japan, and a spectacularly beautiful location. Its temples have opened their doors to visitors for centuries, and a night on the mountain feels like stepping back in time.

Life in a Shingon temple involves a rich variety of sights, scents, and tastes (shojin ryori, or “temple cuisine,” is one of my favorite styles of Japanese cooking). I wanted to experience, and capture, those details to make TRIAL ON MOUNT KOYA leap off the page. Although the temple in my novel is entirely fictitious, it’s based on the real temples where I stayed on Koyasan.   

Landing a novel is always a huge achievement. You bask in its success for a while. Then the inevitable question comes: what’s next?

Fortunately, I’m under contract for two more mystery novels in the Hiro Hattori series, as well as a nonfiction work currently titled 100 Summits: An American Author’s Quest to Scale Japan’s Most Famous Peaks in a Single Year. In fact, I’m writing this from Japan, where I’m researching Hiro Hattori #7 and starting my climbs of the Nihon hyakumeizan (100 famous mountains of Japan) for the 100 Summits project. I’ll be in Japan at least through the summer of 2018, climbing mountains and researching the new mysteries.

In a stroke of delightful good fortune, I’m scheduled to climb to the summit of Mount Koya on July 3—which is also the release date for TRIAL ON MOUNT KOYA.