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  • Writer's pictureMatthew Morgan

What's Significant About Crossover Characters?

Convergent, connected, crossover characters are everywhere. Almost by definition and certainly by design, they are appearing – and then re-appearing and re-re-appearing – all over the literary, cinematic, and televisual landscape. From TV spin-offs such as Better Call Saul to the overlapping Marvel movies to the intertwined paths of characters in series such as A Song of Ice and Fire and the expanding universe of David Mitchell, crossovers are increasing in popularity.

There are myriad reasons for writers to include ubiquitous characters, and yes, it does sometimes come down to the cynical milking of a cash-cow, a lack of imagination, or simply caving to reader expectations. (Sherlock Holmes, though not technically a crossover character, did reappear after his death due to pressure from readers.) But there are sincere artistic reasons a writer might deploy a character for duty between the covers of another book. I want to take a look at what crossover characters, when done well, can achieve for a work of literature by looking at the universe of David Mitchell’s novels, and the ways in which his characters are strange loops.

“In the end, we are self-perceiving, self-inventing, locked-in mirages that are little miracles of self-reference.”

(Douglas Hofstadter, I Am A Strange Loop)

The concept of strange loops was put forward by Douglas Hofstadter, a professor of cognitive science, first in his book Gödel, Escher, Bach and developed later in I Am A Strange Loop. Both books will change your way of seeing, so do have a look at them for full accounts of what I am about to do a disservice to by reducing to simple terms. Essentially, a strange loop is a feedback loop of experiences that, when layered over and among other strange loops, creates a sense of “I” within a person. This is what Hofstadter refers to as a heterarchy, a tangle of strange loops with no well defined beginning or end – you can “enter” it at any point, and by moving continuously in one direction still end up back where you started.

So what does this have to do with crossover characters and shared universes?

A well-constructed shared universe is a form of heterarchy. It is a self-contained system in which the reader can move in any direction by reading the books in any order, and each book will simultaneously expand the universe it describes while eternally returning to the heart of its story (or the story at its heart). In David Mitchell’s shared universe of recurrent souls and immortal beings, there is no clear first or last book, outside of publication dates, and there is no necessary reason to take those as a preferable sequence. Each possible variation of reading order offers a unique view of Mitchell’s universe. Starting with The Bone Clocks, for example – the book that lays out the foundational narrative against which his universe unfolds, as well as examining some of the physics of this cosmos – will offer a significantly different view of the other books. On the other hand, there is a certain element of mystery in those other books when read first, because you don’t know about the nature of souls and immortality in this realm. On the other other hand, reading The Bone Clocks before the other books gives the reader an added insight into the reincarnation featured in Cloud Atlas and the crossover characters of all the books.

This form of heterarchy also accounts for what I see as the central difference between a shared universe and a book series. A series is in some sense chronological. Often it is chronological in a temporal sense, depicting the story as it occurs in linear time. And a series is always chronological in the sense that there is an order in which they must be read to understand the story. Essentially, each book in a series is the next sequential part of a larger sequence, the way chapters operate within a book. A shared universe, however, unfolds in many directions at once and is more interested in the depth of its story than in its sequence of events. This also affects the way crossover characters operate within each type of story.

To take A Song of Ice and Fire as an example of a series, each time Jon Snow pops up in another character’s narrative, it is to progress the story in its onward momentum. In a shared universe, however, the depth of a story is developed with overlapping layers: Discovering Marinus in The Thousand Autumns of Jacob de Zoet after encountering him in The Bone Clocks does not progress the micro- or macro-stories much at all, but it fleshes out, challenges, and changes our understanding of that character and his place in this shared universe. In other words, if a series is intended to get the reader from A to B to C, a shared universe examines the nature and ontology of A, turns to C to add further depth to A, and then takes that conglomeration of A and C as an entry-point to B.

“Meaning lies as much in the mind of the reader as in the Haiku.”

(Douglas Hofstadter, Gödel, Escher, Bach)

If the collected books in Mitchell’s shared universe are a heterarchy, his crossover characters are the strange loops that create it. There are many ways a reader might be introduced to any of these repeat characters. Depending on which order a reader takes these books in, they might meet Hugo Lamb for the second time either knowing his link to a central character from another book or already knowing his metaphysical fate and larger place in this world. These variant forms of background knowledge significantly alter your reading of this character and his stories.

This is a literary version of the cinematic phenomenon known as the Kuleshov Effect: The art of juxtaposing two images in such a way that the first affects how you see the second. A famous example of this was when Hitchcock filmed himself smiling at something off-screen. When this shot is played after a shot of a woman and a baby, that smile is seen as the innocent expression of a kindly old man. When it is played after a shot of a woman in a bikini, his smile is interpreted as that of a lecherous creep. The same, ambiguous expression is viewed differently depending on the context in which it is seen.

In Number9Dream, David Mitchell writes that “a book you finish reading is not the same book it was before you read it”. I agree and would go further to argue that a book is not the same after reading other books, and crossover characters are read differently depending on what you have already seen of them. How we respond to any one of Mitchell’s characters will alter depending on what “shots” we have seen of them already. The Cloud Atlas Sextet written by the character of Frobisher in Cloud Atlas is a vivid example of this phenomenon. Frobisher describes this work as a piece “for overlapping soloists”, a description that seems – while reading Cloud Atlas – to be a perfect description of that particular book. However, if the reader has already read Mitchell’s other books, that description aptly fits the entire universe they describe. And this description, in reaching out from one book to connect with all the others and creating layers out of each text, is doing the very thing it describes the music as doing. The strange loops continue to tangle.

“We are only what we know, and I wished to be so much more than I was, sorely.”

(David Mitchell, Cloud Atlas)

But does all of this amount to much more than a nifty trick, a neat detail for observant readers to notice and be rewarded with the sense of recognising a pattern? Not always, not in all shared universes. Unfortunately, some writers seem to believe that a pattern on its own is significant. But Mitchell manages to transcend mere literary gimmickry, and to explain how, we need to look at “cheap” and “valuable” self-reference in literature.

With cheap self-reference, the artwork descends to a vacuous place of parody for its own sake. Parody is, of course, a useful and often hilarious tool (to quote David Foster Wallace) “to strip off stuff’s mask and show the unpleasant reality behind it”. It is a way of diagnosing ills in society. But once it has done so, it has no constructive equipment for remedying those problems, and so irony and parody eventually turn in on themselves as feedback loops that go in circles forever and, unlike strange loops, do not create something new. We see this kind of thing in the trend of what would otherwise be epic, dramatic movies undercutting their own sincerity with misplaced bathos. The introduction of Deadpool to the informal universe of Marvel superheroes surely signals the end of superhero movies as we know them. When a genre begins to parody itself, something has to give, whether that is the current trend for such films (meaning that, exhausted, the genre fades away) or the conventions that make up the genre, so it changes to become something new. Parody cannot go on indefinitely.

In valuable self-reference, the artwork or elements within it draw attention to themselves not to demonstrate the dexterity of the creator’s mind or massage the reader’s ego by making them feel clever for “getting it”. The self-reference exists to do one of two things, and the best shared universes do both: The self-referential elements deepen the reality in which the story exists, and they make some greater point that refers outside of their own strange loop. David Mitchell succeeds at both.

Without giving away too much to those who are yet to explore David Mitchell’s universe, I can say that reincarnation in both a literal and deeply poetic sense is at the core of the mythology underpinning his books. It is easy to see how crossover characters play into this, both by feeding and by illustrating this theme. There is an important line in Cloud Atlas: “Our lives are not our own. We are bound to others, past and present, and by each crime and every kindness, we birth our future.” This fundamental truth underlies everything that happens in Mitchell’s books, on a small-scale within the intricate themes each book explores and on a large-scale within the meta-story that joins each book and character together. Mitchell’s crossover characters, therefore, are servants to these ideas, manifestations of what his universe explores – they deepen the reality of that universe while describing the ways in which interconnectedness is a creative force.

“Travel far enough, you meet yourself.”

(David Mitchel, Cloud Atlas)

The expansion of existing shared universes and the continued addition of new universes (the Dark Universe, MonsterVerse, Castle Rock, and no doubt more to come) will offer many more opportunities for crossover characters to appear in fiction. But the useful, inventive, fulfilling ways in which crossover characters can add depth to a shared universe have to be carefully and deliberately utilised. They do not occur with any sloppy addition of a character from one book or film into another. That’s why we ended up with the mess that was Suicide Squad. Either the writers thought they could salvage a sloppy and unsatisfying script by thoughtlessly chucking in Batman and the Joker (as far as I can tell, Batman was only there to make viewers think, Huh, I recognise him, cool) or the studio insisted on forcing them in for marketing reasons at the expense of the film. Expect much more of that kind of thing as writers and filmmakers discover the hard way how to do crossovers well and what will turn their audiences off. Fortunately, literature is still relatively behind movies in the crossover game and therefore has a better chance of making the best of crossover characters. David Mitchell has certainly raised the bar for writers and indicated one way in which this sort of thing can be done well.

But it would be sad to forget that a fundamental part of crossover characters, whether done well or done poorly, is a sense of fun. There is a thrill at seeing a beloved character turn up in unexpected places, and it is undoubtedly exciting to see a lead character forced into a subordinate role to see how they cope, or to watch two particular personalities clash in a crossover storyline. And regardless of how writers use such characters and whether they do it at all, readers of all kinds will continue to daydream about fantasy crossovers. My hope is that the best writers will be able to satisfy that sense of imagination while rising to the challenge of writing crossover characters in interesting, unique, and demanding ways. After all, why shouldn’t the things we find fun also be great literature?


• Douglas Hofstadter, I Am A Strange Loop (2007)

• Douglas Hofstadter, Gödel, Escher, Bach: An eternal golden braid (1979)

• David Mitchell, The Bone Clocks (2014)

• David Mitchell, Cloud Atlas (2004)

• George R R Martin, A Song of Ice and Fire (1996 – )

• David Mitchell, The Thousand Autumns of Jacob de Zoet (2010)

• David Mitchell, Number9Dream (2001)

• David Foster Wallace in conversation with Larry McCaffery (1993)

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