Garro: Ashes of Fealty is the thirty-first audio drama for the The Horus Heresy series that was not originally released as part of an anthology or other release. Garro: Ashes of Fealty was first released as an audio drama, and again as part of the Garro main series anthology.
After bringing warning of Horus's treachery to Terra, Nathaniel Garro bade a solemn farewell to his Death Guard brethren and was set upon a more noble path than he ever could have imagined for himself. Now, an old comrade returns -- Meric Voyen, once an Apothecary of the XIV Legion, carrying a deadly cargo within the boundaries of the Sol System. Knowing only too well that to underestimate the powers of the Warp is to fall prey to their corrupting influence, Garro must decide if any good can come of Voyen's mission...and whether or not it is already too late to act against it.
- Flight of the Eisenstein
- Garro: Oath of Moment
- Garro: Legion of One
- Burden of Duty
- Garro: Sword of Truth
- Garro: Shield of Lies
- Garro: Ashes of Fealty
- Garro: Vow of Faith
Nathaniel Garro and his Knights-Errant also make an appearance in the novel Vengeful Spirit. All of these stories, with the exception of Flight of the Eisenstein were later included within the main series anthology novel Garro.
- Garro: Ashes of Fealty (Audio Drama) by James Swallow