Investigating the Sevelynverse

Okay, take a look at these two book covers. 

You see it, right? 

I have both of these books, but far have only read The 7 Deaths of Evelyn Hardcastle, not The 7 Husbands of Evelyn Hugo. A quick Google search tells me that The 7 Deaths came out in 2018, while The 7 Husbands came out in 2017, and they have different publishers. Both of the books were bestsellers. As far as I can tell the stories are different but not, like, SO different as to be completely opposite - the first is an Agatha Christie-style mystery with supernatural elements, and the second is a historical Old Hollywood drama. 

This observation led me to the obvious question: 

How did two separate publishers decide to use all of the following in both of these book titles : The, Seven, of, Evelyn, and then a surname with multiple syllables beginning with “H”? How did this happen when the second book came out, at most, a year after the first?

I’ve been thinking about it for ages and I’ve narrowed it down to four possibilities. 

  1. The publisher of the second book did not know about the name of the first book 

The only real evidence for this argument that I can think of is that one of the books came out in the UK while one came out in the US, but I don’t find that super convincing, because lots of books cross the pond, especially bestsellers, and so I think we can effectively consider the UK and US audiences to be one market for the time being.

  1. The publisher of the second book did know about the name of the first book, but they either thought it wasn’t that similar, or that the similarities wouldn’t make a difference

This seems unlikely. The titles are SO similar and so unique that it seems hard to believe someone whose job it is to think a lot about titles wouldn’t at least factor it in to their marketing strategy. This possibility seems especially unlikely given that the American version of The 7 Deaths was actually called The Seven and a Half Deaths (!!) so they must felt that they had to make some sort of concession.

  1. The publisher of the second book knew about the name of the first book, but they thought that the similarity to the first book would be good for sales

This seems likely. Either the publishers hoped that name recognition would boost sales, kind of like hearing the word Oxyclean over and over again - or they hoped that some people would accidentally buy their book thinking it was the other book. Perhaps a bit unscrupulous, but not strictly wrong

  1. The two books actually exist in the same universe, and this is an elaborate set-up for a secret trilogy - the Sevelynverse - a universe that a secret third book, yet to be released, will neatly tie together 

Think about it. Nearly everyone has an extended universe these days. You can hardly take a step without tripping over an extended universe. And literally everyone has a trilogy. If you’re not writing a trilogy, you may as well set your bank account on fire. (I assume that’s what they say in the Industry.) The only problem with this theory is that it’s impossible to disprove and only the release of a third Sevelyn book will satisfy me. 

Please tell me your theories because I desperately want to know but am dead set against Googling it further on principle.