There are currently ten published books in Jussi Adler-Olsen’s Department Q series. The first book, Mercy introduced readers to the unapologetically surly detective Carl Mørck. Adler-Olsen surprised fans by returning to Department Q with an 11th novel, after the long-held belief that tenth book, Locked In would be the final chapter in the series. The first 5 books in the series are published by Penguin.
Department Q
by5 books in this series
#1 - Mercy
At first the prisoner scratches at the walls until her fingers bleed. But there is no escaping the room. With no way of measuring time, her days, weeks, months go unrecorded. She vows not to go mad. She will not give her captors the satisfaction. She will die first.
Copenhagen detective Carl Mørck has been taken off homicide to run a newly created department for unsolved crimes. His first case concerns Merete Lynggaard, who vanished five years ago. Everyone says she's dead. Everyone says it's a waste of time. He thinks they're right.
The voice in the dark is distorted, harsh and without mercy. It says the prisoner's torture will only end when she answers one simple question. It is one she has asked herself a million times:
WHY is this happening?
Copenhagen detective Carl Mørck has been taken off homicide to run a newly created department for unsolved crimes. His first case concerns Merete Lynggaard, who vanished five years ago. Everyone says she's dead. Everyone says it's a waste of time. He thinks they're right.
The voice in the dark is distorted, harsh and without mercy. It says the prisoner's torture will only end when she answers one simple question. It is one she has asked herself a million times:
WHY is this happening?
#2 - Disgrace
Kimmie's home is on the streets of Copenhagen. To live, she must steal. She has learned to avoid the police and never to stay in one place for long. But now others are trying to find her. And they won't rest until she has stopped moving - for good.
Detective Carl Mørck of Department Q, the cold cases division, has received a file concerning the brutal murder of a brother and sister twenty years earlier. A group of boarding school students were the suspects at the time - until one of their number confessed and was convicted. So why is the file of a closed case on Carl's desk? Who put it there? Who believes the case is not solved?
Carl wants to talk to Kimmie, but someone else is also asking questions about her. They know she carries secrets certain powerful people want to stay buried deep. But Kimmie has one of her own. It's the biggest secret of them all.
And she can't wait to share it . . .
Detective Carl Mørck of Department Q, the cold cases division, has received a file concerning the brutal murder of a brother and sister twenty years earlier. A group of boarding school students were the suspects at the time - until one of their number confessed and was convicted. So why is the file of a closed case on Carl's desk? Who put it there? Who believes the case is not solved?
Carl wants to talk to Kimmie, but someone else is also asking questions about her. They know she carries secrets certain powerful people want to stay buried deep. But Kimmie has one of her own. It's the biggest secret of them all.
And she can't wait to share it . . .
#3 - Redemption
Two boys, brothers, wake tied and bound in a boathouse by the sea. Their kidnapper has gone, but soon he will return. Their bonds are inescapable. But there is a bottle and tar to seal it. Paper and a splinter for writing; blood for ink. A message begging for help.
In Copenhagen's cold cases division Carl Mørck has received a bottle. It holds an old and decayed message, written in blood. It is a cry for help from two boys. Is it real? Who are they and why weren't they reported missing? Can they possibly still be alive?
In Copenhagen's cold cases division Carl Mørck has received a bottle. It holds an old and decayed message, written in blood. It is a cry for help from two boys. Is it real? Who are they and why weren't they reported missing? Can they possibly still be alive?
#4 - Guilt
1987: Nete Hermansen, a young woman brutally assaulted in her youth, sterilised without her consent by a fanatical surgeon, and banished to Sprogo, the island for outcast women is planning her escape and her vengeance. And soon people begin to go missing and no one - certainly not the police - knows why, nor that individual cases are connected.
Today:Carl Mørck and his assistants Assad and Rose in Department Q are examining old missing persons cases and spot a disturbing pattern from 1987 . . .
Today:Carl Mørck and his assistants Assad and Rose in Department Q are examining old missing persons cases and spot a disturbing pattern from 1987 . . .
#5 - Buried
Over three years ago, a civil servant vanished after returning from a work trip to Africa. Missing, presumed dead, the man's family still want answers.
It is one of the many unsolved crimes left for Department Q, Denmark's cold case unit headed up by Detective Carl Morck.
But what Carl doesn't know is that the key to the investigation is in Copenhagen. Fifteen-year-old Marco Jameson is tough, smart and suspicious of police. Sleeping rough and hiding in the shadows is his way of life. But what is he running from - and what does he know worth killing him for?
It is one of the many unsolved crimes left for Department Q, Denmark's cold case unit headed up by Detective Carl Morck.
But what Carl doesn't know is that the key to the investigation is in Copenhagen. Fifteen-year-old Marco Jameson is tough, smart and suspicious of police. Sleeping rough and hiding in the shadows is his way of life. But what is he running from - and what does he know worth killing him for?
Frequently asked questions
How many books are there in the Department Q series?
Is the Department Q series finished?
While Locked In was thought to be the final Department Q novel, Jussi Adler-Olsen’s latest novel was released in the UK in September 2026, meaning Carl Mørck’s story isn’t over just yet. But will there be even more books after that? We just don’t know, but given how beloved the series is, we’re certainly keeping our fingers crossed for more from Copenhagen’s cold case division. Netflix released an adaptation of the first book in the series, Mercy back in 2025. It has been announced that there will be a new series being released in 2027 so there’s loads of opportunity to get stuck into the Department Q universe.
Do you need to read the Department Q books in order?
You can pick up any of the books in any order as each story focuses on a completely different investigation. But, if you are looking to start a new series, we really do recommend reading the books in order. Each character in Copenhagen’s cold-case unit develops and changes across the series and reading the books in publication order really lets you immerse yourself into Adler-Olsen’s dark and gripping world.
How many Department Q books will there be?
As it stands, there are currently 11 published books in the series. The 11th book, No Song for the Dead, was released in the UK in September 2026.