Simultaneous by Eric Heisserer Narrator: Marin Ireland, Ray Porter, Stephanie Sheh
Published by Macmillan Audio on October 28, 2025
Source: Purchased
Genres: Science Fiction, Thriller
Length: 7 hrs 53 mins
Pages: 288
Format: Audiobook
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Federal agent Grant Lukather works for an unknown department of Homeland Security called Predictive Analytics. They look for patterns in tips and chatter to prevent a terrorist event before it happens. One of these calls, about a possible explosion in New Mexico, leads Grant to a case with unimaginable consequences.
He meets Sarah Newcomb, a therapist who uses past-life hypnosis in her treatment but has recently stumbled upon a phenomenon that seems to defy logic. Grant follows this thread to another crime: a copycat killer case in Colorado. With the help of one of Sarah’s patients, they embark upon an investigation that spans multiple states, timelines, and consciousnesses. With limited time and only a tenuous grasp of how this phenomenon works, the unlikely trio are in a race for their lives—past, present, and future.
Full of thrilling reveals, stunning plot twists, and a mordant sense of humor, Simultaneous is a mind-bending, one-of-a-kind thriller by a true genre star.
In theory, I shouldn’t have picked Simultaneous up. I’m not a fan of time travel, and even though this isn’t technically a time-travel book, it does bear similarities to one. Second, they are tracking a serial killer and I typically avoid serial killer books. But it won the 2026 Audie Award for Best Science Fiction, so I picked it up, and it’s a fun ride if you can go along with it.
Grant is a Homeland Security agent in the Department of Predictive Analytics. They essentially investigate “predictions” of terrorist events, always discovering fraud is involved. This time, however, when a pipeline explosion is predicted in advance, Grant is dragged into a different sort of investigation. He meets Sara, a past-life hypnotist, and her client, Marigold. The quirk is that Marigold’s “past life” is actually being lived by another person in the present. Unless it’s all an elaborate con.
The concepts are interesting and the book moves along at a quick pace. The book is big on plot, but the characters maybe needed a little more attention, especially Marigold. Yes, we’re given their backstories and told how they feel about various situations, but it’s maybe a little heavy-handed at times.
It is action-packed and the vocabulary and “science” are accessible for the average listener (aka me). It was full of twists and turns that were impossible to anticipate. Well, one at the end was predictable, but didn’t really affect the plot. The end itself was a bit open, which fit with the concept, but was annoying nonetheless.
The audio version was well done. The narrators all did excellent and there were a few effects that worked well.
About Eric Heisserer
Eric Heisserer grew up in Oklahoma where his father taught ancient history at Oklahoma University. He began his writing career in 1995 with various tabletop game modules, and migrated to screenwriting in 2000 when he sold his first feature script to Artisan Entertainment.
He has since written many feature films including Arrival (2016), based on the Ted Chiang short story “Story of Your Life,” and he has served as showrunner to the Netflix series Shadow and Bone, adapted from Leigh Bardugo’s Grishaverse novels.
His debut novel, Simultaneous, was available October 2025.
Reading this book contributed to these challenges: