Spider-Man: No Way Home's Doctor Strange Box Has a Hidden Backstory That May Have Set Up Multiverse of Madness

Spider-Man: No Way Home finally answered one of its most cryptic lingering mysteries: what was the box Doctor Strange used to try to send the multiverse men back to their home realities? The film's screenplay confirmed its actual name, the Macchina di Kadavus, and the film's VFX team revealed that a whole backstory was conceived for the artifact, one that explains why its destruction might have been the final crack in the dam for Doctor Strange in the Multiverse of Madness, which was still to come when I wrote this in January 2022.

Below, I explain what this box really is and why I think its history was so crucial to the madness ahead.

The Macchina di Kadavus was meant to send the multiverse men home to their deaths

In No Way Home, after all five multiverse men are trapped in the crypt, Strange shows up with the Macchina di Kadavus, an ancient relic that contains Peter's corrupted spell. He says that when he completes the ritual, it will reverse that spell and send them back to their home timelines, where they will die.

That ritual is never fully completed. The box is kept as a failsafe switch and a MacGuffin through the second half of the film, until Green Goblin leaves a pumpkin grenade stuffed inside it. The explosion destroys the box and spills the corrupted spell around Liberty Island. That moment always got one of the biggest audience reactions whenever I watched No Way Home with a new crowd, and I think there is a reason: "we all instinctively sensed that this box was way way too important to be broken."

The Kadavus name points back to Marvel Team-Up and the sorcerer Cagliostro

The Kadavus part of the name comes from the Crystal of Kadavus in Marvel Team-Up #21 from 1974. In that issue, Spider-Man teams up with Doctor Strange to stop the sorcerer Xandu from stealing the crystal, which Xandu needs for a plot to resurrect his deceased wife. The word Kadavus was also likely derived from cadaver, meaning a corpse, specifically the way medical personnel describe a body used for organ harvesting.

The Italian phrasing of Macchina di possibly indicates a shared history with the Italian sorcery of Cagliostro, author of the Book of Cagliostro. In real life, Cagliostro was an 18th century Italian occultist and magician. In Marvel lore, he was an ancient sorcerer rumoured to be an alias of the mystic librarian who, in episode 4 of Marvel's What If, met Strange Supreme in the library of Cagliostro.

As many of us suspected at the time, that creepy Strange variant at the end of the Multiverse of Madness trailer could be the same Strange Supreme from What If episode 4. This box is yet another link from the live action side of the MCU to that particular episode.

Brainstorm's VFX artist says the box once had a more mechanical backstory

The VFX artist from Brainstorm who designed the box told befores & afters that it used to be a much more mechanical kind of puzzle, with a whole backstory that got simplified in the end. He cited the elaborate puzzle work of Chris Ramsay as a reference, saying they wanted the box to look like something that would take a strong wizard to solve. The initial design was all exploded, with Strange bringing all the pieces back together, and the team needed to figure out the right balance of metal, wood and stone to give a sense of an ancient artifact.

Practically speaking, you would assume the box is at least mostly made of wood for MJ to carry it with one hand. That makes sense for ancient relics, the way Indiana Jones and the Last Crusade told us the cup of a carpenter would be mostly wood. But I love how the final design incorporates multiple materials, as if generation after generation of sorcerers upgraded what began as a simple wooden magic box with newer layers of mechanisms and functions, trying to perfect it into something better.

You can see the VFX artists going through that same process, since they revealed several alternate designs as they worked toward the final version. That final design is directly inspired by the Eye of Agamotto. It is mostly gold and green, engraved with runes, and contains inner curved metallic bands that rotate, twist and click into alignment to reveal an inner piece that pops out, just as the Eye of Agamotto does with the Time Stone.

I think the box is a first generation Eye of Agamotto

Doctor Strange said the box's function was to reverse the spell, a kind of Control Z. Based on that function and the clear design parallels with the Eye of Agamotto, it seems clear to me that both artifacts were designed by their sorcerers to do the same thing. They are both undo machines, but the box is the older model: analog and mechanical, requiring assembly, clunkier, more awkward and certainly more prone to theft. The necklace, by comparison, is more portable and protectable, and with the Time Stone, far more applicable.

It is almost like the box was the gen 1 prototype and the necklace was the final form they settled on. Imagine ancient sorcerers like Cagliostro and Agamotto building a mechanism to house a magic that would let them reverse mistakes. They built the Macchina di Kadavus and heralded it as the 1998 iMac G3 of its era. Years later, they realised they could do better than a box you have to puzzle back together every time, so they crammed that same tech into a smaller, sleeker, wearable iPhone form that taps the fuller potential of the magic.

With the Time Stone gone, Strange had to dust off the old relic

The big difference between the two artifacts is the inner battery. The Eye of Agamotto contained the Time Stone, but in the present MCU the Time Stone is gone, atomized. That makes it really weird that Doctor Strange is still wearing an empty Eye of Agamotto necklace, presumably for cosmetic flair, but it explains why he has to dust off this old relic.

Inside the Macchina di Kadavus is a pentagonal prism, a dodecahedron, which holds the corrupted spell. I think this prism could actually be a Crystal of Kadavus like the one from the comics. And the reason the whole artifact is named for cadavers may be the way it fixes the mistake: by killing these foreign elements, returning them to timelines where they become cadavers. That could be why the device would doom all the multiverse men directly to their deaths, even though Lizard and Sandman did not die on screen in their own continuities.

The box may be a challenge to Strange's Hippocratic oath

The cadaver connection also casts this device as a challenge to Strange's own Hippocratic oath, something he has always tried to hold himself to. When we first met Strange in his 2016 film, he argued with Dr. Nicodemus West over whether a brain dead patient could be saved, or whether, as West wanted, that body should be treated like a cadaver.

Now Strange is the one telling Peter that death is their fate. When Peter begs, "come on strange have a heart," Strange responds that "in the grand calculus of the multiverse their sacrifice means infinitely more than their lives." To me, this sounds like a doctor still haunted by his choices in Infinity War and Endgame, choices now coming home to roost as reality melts and unravels before his eyes.

Strange's choices may have left him with no safety net

The imagery matches what we saw in What If episode 4, when Strange bypassed an absolute point to save Christine Palmer. In this universe, I think Strange's choices to help the Avengers undo the snap and help Peter Parker gaslight society were just too much strain on reality. As Mordo warned, the bill has come due. Strange now lives in a reality with no Infinity Stones, the dark stoneless timeline the Ancient One warned about in Endgame, and he has no backup Macchina di Kadavus to contain and purge interdimensional threats.

Potentially, if Multiverse of Madness turned out to be a direct live action depiction of Strange Supreme and the events of What If episode 4, that madness might even include Christine Palmer's death as an absolute destined point. Like poor Xandu, Strange would have no Kadavus to reverse her death. He is just a scared old man with no iPhone to call for help, who dusted off his old desktop to send an email, only for the local ruffians to shove a cherry bomb in it. Now old man Strange is out of options.

Do you think the destruction of the Macchina di Kadavus really was the final crack that broke reality for Doctor Strange?