Fairy Tail Volume 10 by Hiro Mashima
The focus shifts to Erza as the gang enjoys a much-deserved vacation. The vacation is spoiled by the arrival of people from Erza's past who want to kidnap her. She grew up as a slave working on the Tower of Heaven, an R-system intended to resurrect a god who is fueled by hate. Erza's backstory is told in flashbacks as the gang is drawn toward the island where the tower is located.
This story has a lot more drama than comedy. There's still plenty of fighting. The drama is especially tough as children get tortured for rebelling against their enslavement. The story is unresolved by the end, so who knows if a happy ending is in store? The usual notes are at the end of the book, along with a bonus story that's very light, like a filler episode of the anime.
I've slowed down my anime watching so now I am in sync with the manga. I will get the next manga before I watch another episode just to see how that is.