Crime Fiction as Comfort Reading
Murder should not be soothing. For a great many readers it reliably is, and the reason is structural.

The most reassuring genre in the shop is the one about killing people.
It is a genuine oddity. People who avoid the news read four murders a month and sleep well. The explanation is not that readers are ghoulish but that crime fiction promises something almost nothing else does, and then delivers it every single time.
It promises that the disorder will be resolved.

The contract
A body appears, the world stops making sense, someone competent applies attention, and by the last page there is an explanation. The explanation may be bleak but it exists. Very little else in a reader's week works like that.
Literary fiction offers the opposite contract - ambiguity as a mark of seriousness - which is exactly why it is not what you reach for at eleven at night.
Why the series matters more than the book
The comfort compounds across a series. You know the detective, the town, the sergeant who will be wrong in chapter nine. New information arrives inside a familiar frame, which is roughly the definition of a comfortable read.
This is why series readers are so loyal and why a change of narrator is treated as a betrayal.
Where to start if you never have
Not with the most celebrated. Start with a mid-series book by someone prolific, because the machinery will be running smoothly by then and you will find out quickly whether the rhythm suits you.
