With Canterlot in recovery, and the ponies still in angst over the tragedy experienced in perhaps their most precious city, there is little hope for peace of mind in fear of another attack. Princess Twilight, desperate to bring an end to the infestation of dread upon her subjects, gathers a party of allies new and old in order to pursue and eliminate the problem at its source.

With the draconequus who started it all.

But the further Twilight ventures into the depths of despair in her desire to protect her friends and family, she must question whether the pursuit of retribution is worth risking the morality and friendship she'd fought so hard to preserve in the first place.