It’s interesting to unpack how TV series are different from the book.
Charlotte in the book is referred to as “Charlie”, while in the TV series she’s called “Lotte”. In the book, she’s quite successful, and doing a work of an investigator, despite being a stenographer. In the series, she’s struggling to pay her rent with an one-off job at the police station.
Rath is immediately introduced as a “shaker”, having to rely on laundaum to stay in the police. In the book, he’s an occasional drinker, but not much else.
There’s a comic episode in the series which wasn’t present in the books: Rath and Lotte get the photos of their investigations mixed together. Rath works in Vice, and Lotte works in Homicide, so they have to sort together through pornography and murdered victims photos.