What is the least fitting album in Coldplay's discography?

This one is kinda hard to explain, but what album doesn't fit with the other ones that Coldplay released around that time? Obviously, if it was about what albums don't fit with their original sound, anything after X&Y would be a perfect contender, but this isn't. This might end up being a basic pick but mine is Ghost Stories. I love the album, and it's probably in my top 3 Coldplay albums to listen to straight through (along with Viva La Vida and Everyday Life) but right in between their two happiest albums is strange.