SPOILER WARNING: The following article contains major spoilers for “Mighty Thor” #12, on sale now.
"Thor" readers have heard a half dozen different versions of the Mjolnir origin story over the years, all along roughly the same lines: the hammer is forged by dwarves, smelted in the heart of a dying sun/star, and enchanted to be wielded only by the worthy. In "Mighty Thor" #12, however, it is revealed that all these previous stories have left out one crucial element: "The Storm."
In this issue, Mjolnir drags Thor to the Halls of All-Knowing, where the resident librarian reveals the enchanted hammer's "true" origin tale. It begins, predictably, eons ago, when, in gratitude for Odin saving them from Ulik and the trolls, the dwarves grantthe Asgardian a gift of raw Uru, "the most mystical metal in all the realms."
Some time later, Asgard came under threat from "a sentient superstorm" known ominously as The God Tempest, or The Mother of Thunder. Odin battled this "cosmic thunderstorm the size of a galaxy" for days and days before finally being able to trap it inside the Uru.
Being Odin, he then commanded the dwarves to make a weapon of the magical metal, and Mjolnir was born.
However, when Odin tried to wield the hammer, it "refused to be tamed," and tossed him around the galaxy before hurling him back to Asgard. And so, Odin placed enchantments on the hammer to ensure that almost no one could lift it.
So... Is Mjolnir Alive?
The librarian remains skeptical when Thor asks him this question. "Perhaps it was once," he concedes.
However, the depiction of the storm suggests that Mjolnir has something like a conscious will. The storm inside it is described as "a storm that passed judgment -- as if it had a mind of its own." For many years, Odin and the rest of Asgard believed it was his enchantments that decided who was "worthy" of lifting the hammer. Was it instead the will of the storm? (After all, Odin isn't exactly thrilled with the current wielder of the hammer, so he certainly doesn't have complete control.)
The events of issue #11 also suggest that Mjolnir maintains some will of its own, since the hammer took on Jane Foster's form in order to help the human-turned-god. Jane/Thor seemed genuinely surprised at the turn of events, so it isn't something she initiated -- it's something the hammer did on its own.
Of course, these revelations invite the question: what is the extent of Mjolnir's independent powers? And why now, of all times, is the hammer choosing to exercise those powers?
The War of the Realms is Coming!
"Mighty Thor" #12 does drop one big hint as to why Mjolnir might be rearing her/his head now. After Thor leaves the Halls of All-Knowing, the librarian looks ominously at a row of books. After titles like "The Battle of Honeywine Falls" and "The Book of the Mangog" comes a much thicker tome: "The War of the Realms."
"All tales about gods begin the same," he says, "and I'm afraid they end the same as well. Death. Death and destruction. And war. So much war..."