The Duke Who Knew Too Much: Audiobook
Book 1 of the Heart of Enquiry series
According to The Books Insider's catalog data, The Duke Who Knew Too Much runs 10.3 hours as an unabridged audiobook, narrated by Erin Mallon (about 6.8 hours at 1.5× playback speed).
The instrument When will you finish it?
Based on 10.3 hours of listening.
| Your pace | You'll finish in |
|---|---|
| 30 min / day | 21 days |
| 1 hour / day | 11 days |
| 2 hours / day | 6 days |
| 1 hour / day at 1.5× | 7 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 10.3 hours, it runs longer than 65% of the 9,636 Historical (Romance) audiobooks in our catalog.
Catching up on Heart of Enquiry
This is book 1. Books 1 to 6 run 62.2 hours in all.
| Book | Title | Length |
|---|---|---|
| 1 | The Duke Who Knew Too Much | 10.3 hrs |
| 2 | M is for Marquess | 10.7 hrs |
| 3 | The Lady Who Came in from the Cold | 6.8 hrs |
| 4 | The Viscount Always Knocks Twice | 11.4 hrs |
| 5 | Never Say Never to an Earl | 11.1 hrs |
| 6 | The Gentleman Who Loved Me | 11.8 hrs |
More narrated by Erin Mallon
Erin Mallon narrates 270 unabridged audiobooks in our catalog, 2,313 hours in all.
About as long, on the Historical (Romance) shelf
2,517 Historical (Romance) 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
The Duke Who Knew Too Much is book 1 of Grace Callaway's Heart of Enquiry series: a 10.3-hour unabridged recording, read by Erin Mallon, released January 19, 2018, on the Historical (Romance) shelf.
The listen at a glance
- Length
- 10.3 hrs
- Narrated by
- Erin Mallon
- Released
- January 19, 2018
- Format
- Unabridged audiobook
- Language
- English
- Store shelves
- Historical (Romance)
- Series
- Heart of Enquiry #1
- ISBN
- 9781509480968
How to listen to The Duke Who Knew Too Much 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 Duke Who Knew Too Much as an audiobook?
The Duke Who Knew Too Much runs 10.3 hours unabridged. At 1.5× speed that drops to roughly 6.8 hours.
Is The Duke Who Knew Too Much free as an audiobook?
Yes, for new listeners: the trial starts you with three free audiobooks.
Who narrates The Duke Who Knew Too Much?
The Duke Who Knew Too Much is narrated by Erin Mallon.
Is The Duke Who Knew Too Much worth listening to at 1.5× speed?
At 1.5× you'd finish in about 6.8 hours, saving 3.4 hours.