Books like Unfinished Portrait
Agatha Christie
Unfinished Portrait is 304 pages, about 5 hours 34 minutes at 250 words a minute.
12 books to read next
How long each takes
Another Country 6.8 h 
Message in a Bottle 6.7 h 
The Devotion of Suspect X 5.5 h 
The Idea of You 6.8 h 
The Andreou Marriage Arrangement 4.0 h 
An Independent Wife 4.7 h 
Case Study 5.1 h 
The First Wives Club 9.0 h 
Santiago's Love-Child 4.1 h 
Night Film 11.4 h 
His Christmas Bride 3.5 h 
Full House 6.3 h Bar height shows length. Estimated at 250 words a minute.