Gray Matter: The Case of the Autonomous Assassination: Audiobook
Book 4 of the Gray Gaynes series
According to The Books Insider's catalog data, the Gray Matter: The Case of the Autonomous Assassination audiobook runs 4.3 hours unabridged, narrated by Marcus Freeman (about 2.9 hours at 1.5× playback speed).
The instrument When will you finish it?
Based on 4.3 hours of listening.
| Your pace | You'll finish in |
|---|---|
| 30 min / day | 9 days |
| 1 hour / day | 5 days |
| 2 hours / day | 3 days |
| 1 hour / day at 1.5× | 3 days |
You'll finish in – by –
Part of The Audiobook Finish-Time Calculator: the same instrument for any audiobook we measure.
What our data says
- At 4.3 hours, it is shorter than 87% of the 53,570 Mystery, Thriller & Horror audiobooks in our catalog.
Catching up on Gray Gaynes
This is book 4. Books 1 to 3 run 9.4 hours before it; books 1 to 5 run 17.7 hours in all.
More narrated by Marcus Freeman
Marcus Freeman narrates 7 unabridged audiobooks in our catalog, 30 hours in all.
- Gray Tones: The Case of the Elevator Slaying
- Cancer Winner: A Brave Odyssey of Overcoming Cancer’s Challenges and Emerging Victorious on the Other Side of Struggle.
- Gray Area: The Case of the Hellhound Homicide
- Old Gray: The Case of the Cold-Blooded Cremation
- Gray in the City (#1-3): The First Three NYPD Detective Murder Mysteries
About as long, on the Mystery, Thriller & Horror shelf
1,353 Mystery, Thriller & Horror audiobooks in our catalog run within 10% of this length. The most popular on the store:
Computed from 409,794 English-language unabridged audiobooks in The Books Insider catalog (store data read November 3, 2026). Lengths are the store's own running times. Methodology.
About this listen
Gray Matter: The Case of the Autonomous Assassination is book 4 of R.L. Akers's Gray Gaynes series: a 4.3-hour unabridged recording, read by Marcus Freeman, released January 5, 2026, on the Mystery, Thriller & Horror shelf.
The listen at a glance
- Length
- 4.3 hrs
- Narrated by
- Marcus Freeman
- Released
- January 5, 2026
- Format
- Unabridged audiobook
- Language
- English
- Store shelves
- Mystery, Thriller & Horror
- Series
- Gray Gaynes #4
- ISBN
- 9798240129179
How to listen to Gray Matter: The Case of the Autonomous Assassination free
New members at audiobooks.com get three free audiobooks with the trial.
Separately, the store's catalog carries more than 10,000 audiobooks that are always free to stream.
Start listening freeQuestions listeners ask
How long is the Gray Matter: The Case of the Autonomous Assassination audiobook?
Gray Matter: The Case of the Autonomous Assassination runs 4.3 hours unabridged. At 1.5× speed that drops to roughly 2.9 hours.
Is the Gray Matter: The Case of the Autonomous Assassination audiobook free?
Yes, for new listeners: the trial starts you with three free audiobooks.
Who narrates Gray Matter: The Case of the Autonomous Assassination?
Gray Matter: The Case of the Autonomous Assassination is narrated by Marcus Freeman.