Set in 1115, The Black Axe is a prequel to Fall 1152 and follows Celanawe, then a young Guardmouse, and his quest to the island of Ildur to retrieve the Black Axe, a legendary weapon, with companions Em of Appleloft and Conrad.
The series spans six issues which were released between October 2010 and January 2013. A hardcover book was released in July 2013, collecting all six issues, a prologue, an epilogue, and other assorted extras.
Petersen originally planned to make this a shorter, four-issue anthology series with each issue documenting a different Celanawe adventure. However, when developing the outline for the series he found that Celenawe's history could be better told as a "quest" narrative. This longer character arc necessitated six issues of material.
By early 2010, Petersen had completed the cover for the first issue, and he finished outlining this issue in April that year.
Archaia published Issue 1 in October 2010. Issues 2 and 3 followed in April and September 2011, respectively, and Issues 4 and 5 in January and August 2012, respectively. The final issue was released in January 2013. As with Fall 1152 and Winter 1152, each issue was accompanied by a pin-up by a guest contributor(s): Alex Sheikman, Sean Rubin, Duncan Fegredo, Charles Paul Wilson III, Shane-Michael Vidaurri and Mike Mignola & Dave Stewart.
Petersen released a collected hardcover in July 2013, collecting all six issues as Chapters One through Six, the 2010 Free Comic Book Day one-shot Spring 1153 as a prologue, a short epilogue, a twenty-two page section of maps, guide pages, and cutaways, and a gallery of the aforementioned pin-ups.
- See also: Mouse Guard: Spring 1153
The prologue collects Petersen's first Free Comic Book Day one-shot, Spring 1153, which was originally released on 1 May 2010. It follows an entry in the Matriarch Gwendolyn's journal and the doings of the Mouse Guard across the Mouse Territories. But for the exclusion of the cover, the prologue remains unchanged from the original version.
Writing from her office at Lockhaven in the spring of 1153, six days before day and night are equal, Gwendolyn dictates that the mice have experienced dangerous weather for the past eight days. Rivers and streams are overflowing, and she has sent out almost all her Guardmice to rebuild and bring order to the Territories.
Annika and Cedric monitor a pack of wolves near Elmoss, while Gwendolyn narrates that predators are waking and breeding. We see Sela and Cerise protecting some harvesters at Rootwallow, and Gwendolyn wonders as to the fate of Lieam, who has been missing since the end of winter. While concerned for Lieam's fate, Gwendolyn writes that she cannot spare any of her mice to look for him.
We see Ewing and Waldon gathering timber near Whitepine, and Saxon and Sienna assisting the apiary keeper with harvesting honey from the Lockhaven bees. Gwendolyn assures any later Matriarch reading this diary that she wishes for nothing but Lieam's safe return.
Vinson, Elymis and Aeren mark the Scent Border, and Gwendolyn discusses the first seasonal summit between the leaders of the settlements, which is to occur in 10 days time. The leaders are to be escorted by the sons and daughters of their respective settlements who wish to become Guardmice — a "trial by rain" as Gwendolyn terms it.
The Matriarch turns her mind toward the death of Celanawe, while we see Kenzie and Sadie fishing near Lillygrove and Oakgrove. We see Bastian and Delvin battling a rampaging snapping turtle near Grasslake, while Gwendolyn questions the ability to protect the Territories without the Black Axe. Then, Pearse, Erwynn and Feagan fight a badger attacking Dorgift and/or Gilpledge. Gwendolyn reflects briefly on her declaration of war against the Darkheather weasels in 1149.
Finally, we see Isabel leading two hares towards a large, looming cave. The hares bear a cart laden with all the resources we have just seen the Guardmice gathering: berries and honey, and the corpses of the fish, the turtle and the badger. As Gwendolyn writes her parting thought — that the Guard can only placate these troubles until they have a new hero in which to believe — we see a giant bear emerge from the cave and consider the cart: a gift of placation for this largest of predators.
Chapter One collects The Black Axe Issue 1, which was first released in October 2010. It follows Celanawe's meeting of Em at Frostic and his discovery of his lineage and connection to the Black Axe.