When Jonah and Katherine travel to early 1900s Switzerland and Serbia to return Albert Einstein's daughter, Lieserl, to history, her mother Mileva grasps entirely too much about time travel and has no intention of letting her daughter go.

Thirteen-year-old Jonah and 11-year-old Katherine travel through time to 1918 Russia just as Alexei, Anastasia and the rest of Tsar Nicholas II's family are about to be executed. Author's note includes facts about the Romanovs and the mystery surrounding their deaths.

Jonah and Katherine journey to 1918 with the Romanov children in the sixth book of the New York Times bestselling The Missing series, which Kirkus Reviews calls “plenty of fun and great for history teachers as well.” It’s a paradox: When Jonah and Katherine find themselves on a mission to return Alexei and Anastasia Romanov to history and then save them from the Russian Revolution, they are at a loss. Because in their own time, the bones of Alexei and Anastasia have been positively identified through DNA testing. What hope do they have of saving Alexis and Anastasia’s lives when the twenty-first century has proof of their deaths?

After returning the missing children from history to their original time periods, thirteen-year-old Jonah must save time itself when aviator Charles Lindbergh mysteriously appears and kidnaps Jonah's sister.

After a mysterious appearance by Charles Lindbergh, it’s up to Jonah to save his town in the seventh book of the New York Times bestselling The Missing series, which Kirkus Reviews calls “plenty of fun and great for history teachers as well.” It’s morning as usual at the Skidmore household—until Charles Lindbergh, the famous historical pilot, appears in their living room. Jonah can hardly believe his eyes—and then Lindbergh grabs Katherine and vanishes again. And that’s not all. Chip, Andrea, and all the other children from the plane have disappeared too. And worst of all, Jonah’s parents and all the other adults in his town have de-aged into children. Jonah is the only one left, and the only one who can save everyone. With the help of de-aged JB and Angela, he has to collect the clues. And they lead directly back to Gary and Hodge, and a terrible plot that could mean the end of everything Jonah has ever loved. Can Jonah put the pieces together before time runs out?

Jonah’s new twin must time travel and face off against his siblings’ worst enemy in order to save the future—and his family—in the eighth and final book of the New York Times bestselling The Missing series, which Kirkus Reviews calls “plenty of fun and great for history teachers as well.” After traveling through history multiple times and finding out his original identity, Jonah thought he’d fixed everything. But some of his actions left unexpected consequences. His parents—and many other adults—are still stuck as teenagers. And now Jonah has a new sibling, an identical twin brother named Jordan. As odd as all this is for Jonah, it’s beyond confusing for Jordan. How does everyone in his family have memories of Jonah when he doesn’t? How can his annoying kid sister Katherine speak so expertly about time travel—and have people from the future treating her with respect? A few rash moves by Jordan send them all into the future—and into danger. What if he’s also the only one who can get them back to safety, once and for all?

In this page-turning middle grade series by New York Times bestseller Margaret Peterson Haddix, Colin and Nevaeh, whose parents own rival junk-removal businesses, uncover mysteries hidden in attics and basements and discover how trash can become treasure. In The Secret Letters, Colin and Nevaeh find vintage letters that lead to interlocking mysteries from the 1970s and '80s, and they learn about "women's lib," the ERA, and other social issues from that time in history--and the way echoes from that era affect Colin and Nevaeh themselves. When Colin finds a shoebox full of letters hidden in a stranger's attic, he knows he's supposed to throw them away. That's his summer job, getting rid of junk. But Colin wants to rescue the letters--and find out what really happened to best friends Rosemary and Toby way back in the 1970s. Meanwhile, across town, Nevaeh also finds a mysterious letter. But this one reads like a confession to a crime. And Nevaeh knows her father, the "Junk King," expects her to join the rest of the family in blaming a single suspect: his business rival, Colin's mom. But that's not what Nevaeh wants, either. Even as one set of letters bring Colin and Nevaeh together, the one Nevaeh found threatens to tear them apart. Is their new friendship as doomed as Rosemary and Toby's? Each book in the Mysteries of Trash and Treasure series will examine a different time period in history and make readers think about how we value the stuff we hold on to--and what it is that makes it valuable.

Colin and Nevaeh, whose parents own rival junk-removal businesses, uncover mysteries hidden in attics and basements and discover how trash can become treasure. In The Secret Letters, Colin and Nevaeh find vintage letters that lead to interlocking mysteries from the 1970s and '80s, and they learn about "women's lib," the ERA, and other social issues from that time in history--and the way echoes from that era affect Colin and Nevaeh themselves. When Colin finds a shoebox full of letters hidden in a stranger's attic, he knows he's supposed to throw them away. That's his summer job, getting rid of junk. But Colin wants to rescue the letters--and find out what really happened to best friends Rosemary and Toby way back in the 1970s. Meanwhile, across town, Nevaeh also finds a mysterious letter. But this one reads like a confession to a crime. And Nevaeh knows her father, the "Junk King," expects her to join the rest of the family in blaming a single suspect: his business rival, Colin's mom. But that's not what Nevaeh wants, either. Even as one set of letters bring Colin and Nevaeh together, the one Nevaeh found threatens to tear them apart. Is their new friendship as doomed as Rosemary and Toby's?

Colin and Nevaeh are great at finding things. After all, they found each other and became best friends--even though their parents are business rivals. They also found hidden boxes of secret letters, which led them to unravel mysteries about kids from the 1970s. But when they started Mystery Solvers Inc., they didn't expect to be asked to find a ghost. Ree recruits them to investigate a series of old, spooky photos left behind in her family's new house. The photos show a boy who looks totally see-through. And in some, he's in a coffin. That's not so odd for Ree, who lives above a funeral home. But when Colin and Nevaeh start investigating, they discover other sightings of the boy--and other secrets Ree is hiding. The more clues they find, the more they realize this mystery goes back to a time called the Great Depression. Will history, once again, help them solve the case?

Cecelia looks like a peasant girl and lives in a village so small that it's not even on the map. But she knows that secretly, she is the true princess, hidden away as a baby to be kept safe from the enemies of the kingdon. A commoner named Desmia was placed on the throne as a decoy. Cecelia has always known that when it was safe, she would be taken out of hiding and returned to her rightful place on the throne. Then danger finds her in her village, and Cecelia has to act. With the help of her best friend Harper, she decides to take matters into her own hands, relieve Desmia of the the crown, and take up her own rule. But when they venture from their small village to the capital city and into the famed Palace of Mirrors, Harper and Cecelia discover that all is not as it seems, and that they have placed themselves in more danger than ever before.

Eleven-year-old Marin and her neighbor Charley hope that by preventing a disaster that occurred twenty years ago, they can save Charley's dad from a future of guilt and self-destructive behavior.

New York Times bestselling author Margaret Peterson Haddix, the master of cliffhangers, delivers a pulse-pounding mystery , full of secrets, surprises, and the power of family. Now available in paperback. One minute they're there: laughing and having fun at the house next door. The next minute, the teens are gone. Like magic. Marin can't believe her eyes. Who are they? Can anyone else see them? What makes them so happy? Marin is lonely in this new town of hers and eager to figure out more. Then she meets Charley, who reveals that he knows about them, too. He calls them the "Remarkables." Charley warns her to stay away from the Remarkables--and him. Charley and Marin both have painful secrets they're holding on to, but could solving the mystery of the Remarkables help them both? Haddix also grounds the story with real issues that many children face. Characters deal with the complexities of bullying, the guilt children experience when parents have addiction issues, and the uplifting power found in strong families of all shapes and sizes.

From master of suspense author Margaret Peterson Haddix comes another page-turning stand-alone adventure perfect for fans of Cog and Bad Magic. No matter what anyone tells you, I'm real. That's what the note says that Max finds under his keyboard. He knows that his best friend, Josie, wrote it. He'd know her handwriting anywhere. But why she wrote it--and what it means--remains a mystery. Ever since they met in kindergarten, Max and Josie has been inseparable. Until the summer after fifth grade, when Josie disappears, leaving only a note, and whispering something about "whatnot rules." But why would Max ever think that Josie wasn't real? And what are whatnots? As Max sets to uncover what happened to Josie--and what she is or isn't--little does he know that she's fighting to find him again, too. But there are forces trying to keep Max and Josie from every seeing each other again. Because Josie wasn't supposed to be real. This middle grade thriller from Margaret Peterson Haddix delves into the power of privilege, the importance of true friendship, and the question of humanity and identity. Because when anyone could be a whatnot, what makes a person a real friend--or real at all?

From master of suspense author Margaret Peterson Haddix comes another page-turning stand-alone adventure perfect for fans of Cog and Bad Magic. No matter what anyone tells you, I'm real. That's what the note says that Max finds under his keyboard. He knows that his best friend, Josie, wrote it. He'd know her handwriting anywhere. But why she wrote it--and what it means--remains a mystery. Ever since they met in kindergarten, Max and Josie have been inseparable. Until the summer after fifth grade, when Josie disappears, leaving only a note, and whispering something about "whatnot rules." But why would Max ever think that Josie wasn't real? And what are whatnots? As Max sets to uncover what happened to Josie--and what she is or isn't--little does he know that she's fighting to find him again, too. But there are forces trying to keep Max and Josie from ever seeing each other again. Because Josie wasn't supposed to be real. This middle grade thriller from Margaret Peterson Haddix delves into the power of privilege, the importance of true friendship, and the question of humanity and identity. Because when anyone could be a whatnot, what makes a person a real friend--or real at all?

From New York Times bestselling author Margaret Peterson Haddix comes a haunting novel about friendship and what it really means to be a family in the face of lies and betrayal. Fourteen-year-old Avery Armisted is athletic, rich, and pretty. Sixteen-year-old Kayla Butts is known as “butt-girl” at school. The two girls were friends as little kids, but that’s ancient history now. So it’s a huge surprise when Avery’s father offers to bring Kayla along on a summer trip to Spain. Avery is horrified that her father thinks he can choose her friends—and make her miss soccer camp. Kayla struggles just to imagine leaving the confines of her small town. But in Spain, the two uncover a secret their families had hidden from both of them their entire lives. Maybe the girls can put aside their differences and work through it together. Or maybe the lies and betrayal will only push them—and their families—farther apart. Margaret Peterson Haddix weaves together two completely separate lives in this engaging novel that explores what it really means to be a family—and what to do when it’s all falling apart.

From New York Times bestselling author Margaret Peterson Haddix comes a novel about friendship and what it really means to be a family in the face of lies and betrayal. Fourteen-year-old Avery Armisted is athletic, rich, and pretty. Sixteen-year-old Kayla Butts is known as “butt-girl” at school. The two girls were friends as little kids, but that’s ancient history now. So it’s a huge surprise when Avery’s father offers to bring Kayla along on a summer trip to Spain. Avery is horrified that her father thinks he can choose her friends—and make her miss soccer camp. Kayla struggles just to imagine leaving the confines of her small town. But in Spain, the two uncover a secret their families had hidden from both of them their entire lives. Maybe the girls can put aside their differences and work through it together. Or maybe the lies and betrayal will only push them—and their families—farther apart. Margaret Peterson Haddix weaves together two completely separate lives in this engaging novel that explores what it really means to be a family—and what to do when it’s all falling apart.