Books like The Disappearance by Bentley Little

After a tragic gunshot wound, former chief detective Carl Mørck is reassigned to cold‑case work, where he is drawn into a five‑year investigation of a missing Danish politician.

A family’s idyllic summer party at a grand estate in Cornwall turns into a desperate search when six‑year‑old Theo vanishes, leaving the house abandoned and the siblings torn apart.

Detective Stephen Moran has been waiting for his chance to join Dublin’s Murder Squad when sixteen-year-old Holly Mackey arrives in his office with a photo of a popular boy whose body was found at a girls’ boarding school a year earlier. The photo had been posted at “The Secret Place,” the school’s anonymous gossip board, and the caption says “I KNOW WHO KILLED HIM.” Stephen joins with Detective Antoinette Conway to reopen the case—beneath the watchful eye of Holly’s father, fellow detective Frank Mackey. With the clues leading back to Holly’s close-knit group of friends, to their rival clique, and to the tangle of relationships that bound them all to the murdered boy, the private underworld of teenage girls turns out to be more mysterious and more dangerous than the detectives imagined.

"I very much need to be dead." These are the chilling last words left by a man who had everything to live for but took his own life. In the void that remains stands his widow, FBI agent Jane Hawk, surrounded by questions destined to go unanswered unless she does what all the grief and fury inside her demand: Find the truth, no matter what. People of talent and accomplishment, people seemingly happy and sound of mind, have recently been committing suicide in surprising numbers. A disturbing pattern is beginning to emerge. Jane is determined to give up everything to find out why. And if that means going rogue and becoming America's Most Wanted, then so be it. Those arrayed against her are legion, and devoted to protecting something profoundly important-or terrifying-enough to exterminate any and all in their way. But Jane is as clever as these enemies are cold-blooded, as relentless as they are ruthless. And she is driven by a righteous rage they can never comprehend. Because it is born of love.

Late one night, journalist Mikael Blomkvist receives a phone call from a source claiming to have information vital to the United States. The source has been in contact with a young female superhacker -- a hacker resembling someone Blomkvist knows all too well. The implications are staggering. Blomkvist, in desperate need of a scoop for Millennium, turns to Salander for help. She, as usual, has her own agenda. The secret they are both chasing is at the center of a tangled web of spies, cybercriminals, and governments around the world, and someone is prepared to kill to protect it.

In Boston, George Foss is drawn into a murder-swathed world when the enigmatic Liana Dector, a fugitive killer, turns to him for help and his past threatens to unravel everything.