Simon R. Green books in order
21 books in the catalogue, about 137 hours of reading in all; the shortest takes 3 hours and the longest 11 hours.
4 series and 2 standalone books in the catalogue.
Nightside
12 books 1 
Something from the Nightside 4.7 h 2 
Agents of Light and Darkness 4.3 h 3 
Nightingale's Lament 4.5 h 4 
Hex and the City 5.3 h 5 
Paths Not Taken 5.7 h 6 
Sharper Than A Serpent's Tooth 5.6 h 7 
Hell to Pay 5.0 h 8 
The Unnatural Inquirer 4.7 h 9 
Just Another Judgement Day 5.0 h 10 
The Good, the Bad, and the Uncanny 5.1 h 11 
A Hard Day's Knight 5.5 h
Something from the Nightside 4.7 h 2 Agents of Light and Darkness 4.3 h 3 Nightingale's Lament 4.5 h 4 Hex and the City 5.3 h 5 Paths Not Taken 5.7 h 6 Sharper Than A Serpent's Tooth 5.6 h 7 Hell to Pay 5.0 h 8 The Unnatural Inquirer 4.7 h 9 Just Another Judgement Day 5.0 h 10 The Good, the Bad, and the Uncanny 5.1 h 11 A Hard Day's Knight 5.5 h 12 The Bride Wore Black Leather length not known
Deathstalker
8 books 1 
Deathstalker 10.6 h 2 
Deathstalker Rebellion 10.6 h 3 
Deathstalker War 10.6 h 4 
Deathstalker Honour 11.4 h 5 
Deathstalker Destiny 8.3 h 
Deathstalker Return 8.7 h
Deathstalker 10.6 h 2 Deathstalker Rebellion 10.6 h 3 Deathstalker War 10.6 h 4 Deathstalker Honour 11.4 h 5 Deathstalker Destiny 8.3 h 6 Deathstalker Legacy length not known
7 Deathstalker Return 8.7 h 8 Deathstalker Coda length not known
