Marvel has published the second issue of the Avengers: Infinity War Prelude, the official prequel comic book to the next Avengers movie. The first issue of prelude was focused on events set between Captain America: Civil War and Infinity War. It revealed how Shuri will cure the Winter Soldier from Hydra's brainwashing; what Steve Rogers and his allies have been up to in the last few years; and just why Vision and Scarlet Witch aren't with either Avengers team.

The second issue is more of a primer on what Marvel fans already know about the Infinity Stones. It's essentially a long conversation between Doctor Strange and Kamar-Taj's librarian, Wong. They're discussing recent events in the MCU, and are well aware of how the Infinity Stones have been brought into play. Although this issue doesn't contain many major spoilers, it does reveal some important details.

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Doctor Strange And The Sorcerers Are On To Thanos

It seems the Masters of the Mystic Arts are well aware of the coming threat. Wong is able to tell Strange the Earth-bound history of the Infinity Stones. He describes - in detail - the Red Skull's acquisition of the Tesseract decades ago. He sums up S.H.I.E.L.D.'s unwise experimentation with the Tesseract's power, and even understands Loki's role in the Battle of New York. No doubt the Avengers would be disturbed at the depths of Wong's knowledge, as he goes on to describe Stark's creation of Ultron in detail. Incredibly, he's even aware that the Reality Stone was used at the Convergence in London. Wong isn't aware that the Power Stone has been retrieved from Morag, although he seems to know it had been left on that barren world in the first place.

It's clear the Ancient One was aware of the threat of the Infinity Stones. She had, after all, inherited the mantle of Sorcerer Supreme; and according to Wong, the first Sorcerer Supreme wielded the Time Stone out of necessity. Under the Ancient One's leadership, the Masters of the Mystic Arts monitored the threat of the Infinity Stones. Whether through sorcery or through spies, they kept a careful eye out for any developments, and rightly interpreted them. The Infinity Stones are clearly being brought into play once more, and the Masters of the Mystic Arts are deeply concerned.

In fact, Wong's knowledge of the details actually seems to offer a tantalizing hint; Agamotto, the first Sorcerer Supreme, may have been one of the ones who hid the Infinity Stones in the first place. After all, the Tesseract was guarded by another religious (possibly mystical?) cult for centuries, and the Power Stone was hidden on an ancient world. The fact the Masters know where the Power Stone was hidden is certainly suggestive.

The Tesseract Contains The Space Stone

Fans have long suspected that the Tesseract is actually a cube that contains the Space Stone. That has finally been confirmed in the Infinity War Prelude comic. Wong describes the Tesseract as "an object of containment for what we know to be the Space Stone." The trailer for Infinity War revealed that Thanos will acquire the Space Stone, so it's safe to say he will break open the Tesseract.

Read More: Marvel Reveals The Secrets of the Infinity Stones

The Red Skull May Still Be Alive

The comic is filled with various flashback scenes - but the most interesting is no doubt this one, referencing The First Avenger. Previous comic book adaptations had presented this as the Red Skull's death, with explosions of blue energy. This time around, though, the art instead seems to suggest that the Red Skull was transported by the Space Stone. Fans have long suspected this, but it seems to suggest Red Skull isn't actually dead; rather, he was sent into the depths of space to who knows which alien world. Johann Schmidt could still menace Captain America.

The Real Reason Doctor Strange Trapped Loki

Doctor Strange talking to Thor in Thor: Ragnarok

In an amusing scene, the Infinity War Prelude comic reveals why Doctor Strange was so concerned when he discovered Loki's presence on Earth. Wong was partway through telling Strange about the Infinity Stones, and the two found Loki disturbing; the God of Mischief has wielded not one, but two, Infinity Stones, after all. That's why Strange intervened directly, trapping Loki and summoning Thor to see him. it's a smart detail, one that adds extra depth to Strange's cameo in Thor: Ragnarok.

It's also an amusing reinterpretation of that scene. Aside from the Masters of the Mystic Arts, Thor is the only one who has truly realized the Infinity Stones are in play. In fact, the Odinson has spent two years pursuing the Infinity Stones. In Thor: Ragnarok, though, he meets with Stephen Strange - who is even wearing the Eye of Agamotto, the Time Stone. Neither trusts the other, and Strange simply tells Thor where Odin is.

RELATED: Thor: Ragnarok’s Deleted Scenes Hide Odin’s Original Death

The Soul Stone May Be The Most Dangerous Of All

Right now, the greatest mystery of the MCU is the location of the Soul Stone. Some fans still believe it to be wielded by Heimdall, insisting that's how he sees every soul across the Realms; although convenient, this explanation seems less likely after Thor: Ragnarok. Besides which, in Thor: The Dark World the Asgardians expressed concern at having more than one Infinity Stone on Asgard (and they already have the Tesseract). Another theory has long been that the Soul Stone is in WakandaBlack Panther's supernatural overtones do make that possible, but again the film contains no explicit reference to the final Infinity Stone. Its location remains a mystery.

In one disturbing scene, Wong tells Strange that little is known about the Soul Stone. "If what is known turns out to be true," he tells Strange, "It could prove to be the biggest threat of them all." As he speaks, Wong is looking at one of his books; frustratingly, the book is written in another language, so nothing can be discerned by readers. The page includes a picture of space, with planets visible. That may simply be a reference to the cosmic nature of the Infinity Stones; alternatively, in the comics the Soul Stone actually contains an entire plane of existence, one in which souls can reside. It may be a nod towards that.

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All in all, this second issue doesn't drop many hints or clues. It sets up Doctor Strange as the Marvel hero who knows all about the Infinity Stones; that knowledge will certainly prove useful when Thanos finally arrives on Earth. The comic does confirm a long-standing theory about the Tesseract, and it certainly reassures fans that the Soul Stone will soon appear. Beyond that, it's most notable element is a subtle but entertainment rewrite of Thor: Ragnarok, adding extra depth to the meeting between Strange and Thor.

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