Series reading guide · updated 2026
Boundary Books in Order
Every Boundary book in publication order — 6 in total, spanning 2006–2020.
Publication Order of Boundary Books
| # | Title | Year | Get it |
|---|---|---|---|
| 1 | Boundary | 2006 | Amazon US UK |
| 2 | Threshold | 2010 | Amazon US UK |
| 3 | Portal | 2013 | Amazon US UK |
Publication Order of Boundary: Castaway Books
| # | Title | Year | Get it |
|---|---|---|---|
| 1 | Castaway Planet | 2015 | Amazon US UK |
| 2 | Castaway Odyssey | 2016 | Amazon US UK |
| 3 | Castaway Resolution | 2020 | Amazon US UK |
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