Reading order
| # | Title | Published | Author | Buy on Amazon |
|---|---|---|---|---|
| 1 | Terms of Enlistment | 2013 | Marko Kloos | Buy |
| 2 | Lucky Thirteen | 2013 | Marko Kloos | Buy |
| 3 | Measures of Absolution | 2013 | Marko Kloos | Buy |
| 4 | Evakuace | 2014 | Marko Kloos | N/A |
| 5 | Blokáda | 2015 | Marko Kloos | N/A |
| 6 | Lines of Departure | 2014 | Marko Kloos | Buy |
| 7 | Dezerce | 2016 | Marko Kloos | N/A |
| 8 | Angles of Attack | 2015 | Marko Kloos | Buy |
| 9 | Fields of Fire | 2017 | Marko Kloos | Buy |
| 10 | Chains of Command | 2016 | Marko Kloos | Buy |
| 11 | Protiúder | 2018 | Marko Kloos | N/A |
| 12 | Orders of Battle | 2020 | Marko Kloos | Buy |
| 13 | Points of Impact | 2018 | Marko Kloos | Buy |
| 14 | Centers of Gravity | 2022 | Marko Kloos | Buy |
| 15 | Echoes of Silence | 2025 | Marko Kloos | Buy |
The Frontlines series launched Marko Kloos’ career when “Terms of Enlistment” (2013) found a large audience as a self-published novel. The series follows Andrew Grayson, who enlists in the military to escape the poverty of a future Earth, only to find himself fighting an interspecies war against the Lankies, enormous alien creatures that terraform human colony worlds. The books chart Grayson’s progression from recruit to experienced soldier across an escalating conflict.
The series runs fifteen entries including the main novels and shorter works like “Lucky Thirteen” and “Measures of Absolution.” Key installments include “Lines of Departure” (2014), “Angles of Attack” (2015), “Fields of Fire” (2017), and the more recent “Orders of Battle” (2020) and “Centers of Gravity” (2022). Kloos draws on his own military background to write combat and military culture with an authenticity that sets the series apart. The Lankies are a genuinely alien threat, and the human response to them drives both the military action and the political tensions that run through the books.