What began as an Iron Warriors invasion expecting assured victory blossomed into the single largest tank engagement of the entire Horus Heresy, leaving the formerly verdant world of Tallarn a dusty wasteland littered with thousands of wrecked vehicles. Journal Tactica: The Battle of Tallarn Part One chronicles the opening stages of this apocalyptic war, and includes extensive background lore as well as a new Legendary Mission that pits a squadron of Iron Warriors vehicles against a crushing ambush from Tallarn resistance fighters.

This book also includes a new mission pack for Armoured Spearhead engagements, which are designed to work with armies packed to the brim with tanks and armoured vehicles. Accordingly, there are also rules for Dracosan Command Tanks and Spartan Prometheus Command Tanks, as well as the new Solar Auxilia Rapier Carriers and Charonite Ogryns.