Captain Tybalt Marr of the Sons of Horus, so often overlooked by his more glory-hungry brethren, returns to his Legion in triumph. However, his boasts of having slain the infamous Iron Hands warleader Shadrak Meduson soon fall flat when he learns of the recent assassination attempt on Horus himself.

Gathering his forces upon the conquered world of Dwell, Marr returns to battle against the Shattered Legions, determined to earn his rightful place in history.