The Sinister Summer Series

Giant battle robots! Cotton candy betrayal! Blasts from the past! And the ultimate challenge to stay true to themselves and each other await Theo and Alexander in the final book in the tragic series about the Sinister-Winterbottom twins, who must solve one wretched mystery after the next, brought to you by #1 NYT bestselling author Kiersten White.

Trapped in Aunt Saffronia’s spectral house, Theo and Alexander must work together to escape, stop their newfound nemesis Essa and her henchman Edgaren’t, save Wil and their friends, find their parents, and maybe, just maybe, get things back to normal.

Following the clues left behind, the twins find themselves at Siren’s Song Seaside Amusement Park. Old faces and new surprises await them in a park that was built to lure in visitors…and their secrets.

As they get closer to answers, the twins are left with the biggest question of all: Who is Essa really, and why is she so determined to find their parents?

Book four in the tragic series about the Sinister-Winterbottom twins, who must solve one wretched mystery after the next, brought to you by #1 New York Times bestselling author KIERSTEN WHITE. The electrifying penultimate adventure finds the Sinister-Winterbottoms at the manor of Mr. Frank and Dr. Stein!

After escaping from Edgaren’t and Dr. Jay, the Sinister-Winterbottoms and their friends arrive at Stein Manor Science Camp. They all work together to distract the friendly teenage camp director so they can explore and look for clues about where their parents might be.

Meanwhile, Theo and Alexander settle on a daring plan. They know exactly where Edgaren’t is going to be: coming for them, and the books. This time, they’ll be ready. This time, they’ll get answers. And this time, they won’t trust the adult in charge, which is easy enough when it’s enormous, lurking, unfriendly Mr. Frank. But as they get closer to opening the books and their parents’ histories, an unexpected foe is watching everything they do. . . .

Fake volcanoes! Real sea caves! Strangely modified frogs! Startling betrayal! And a lightning-struck manor! all combine for the electrifying penultimate Sinister Summer adventure.

The third book in the middle-grade series that’s part Scooby-Doo, part A Series of Unfortunate Events, and entirely genius! Follow the Sinister-Winterbottoms on their most outrageous adventure yet, when they find themselves at a normal summer camp!

After leaving the Sanguine Spa in pursuit of Edgaren’t, the kids find themselves at a mysterious summer camp, Camp Creek. There are lake games and happy counselors, and there’s even a tie-dye cabin. It’s all very . . . normal.

But if Theo and Alexander know one thing, it’s that normal doesn’t always mean good. When everyone around her starts acting strange, Theo wonders if maybe the fumes from the tie-dye cabin are seeping into their brains, and she resolves to investigate what’s really going on at Camp Creek.   

The third book in #1 New York Times bestselling author Kiersten White’s Sinister Summer series continues the adventures of the Sinister-Winterbottoms and their aunt, who never saw a discount vacation destination she didn’t love.

The spooky summer adventures of the Sinister-Winterbottom twins continue in another gothic mystery: can Theo and Alexander solve the secret of the Sanguine Spa? The second book in the new Sinister Summer series by #1 NYT bestselling author Kiersten White, called “perfect for fans of Lemony Snicket, Edward Gorey, and Roald Dahl,” by Shelf Awareness.

After leaving Fathoms of Fun, the kids are on their way to the next odd summer destination their aunt has chosen for them. This time, they find themselves dropped off at the Sanguine Spa in the “little Transylvania Mountains.” There they meet the owners: Mina, her mysterious little sister, Lucy (who is extremely pale, can’t go in the sunlight, and has an affinity for hanging upside down from the ceiling), and their intimidating guardian, the Count.  

When the Count sends all the children in the spa on a scavenger hunt, the Sinister-Winterbottoms use the excuse to snoop around and discover that this spa may be more than just eerie—it might also hold clues to what happened to their parents. When Wil starts to show vampiric symptoms, the twins resolve to investigate what’s really going on at the Sanguine Spa.  

The second book in the Sinister Summer series continues the adventures of the Sinister-Winterbottoms and their aunt who never saw a discount vacation destination she didn’t love.

A middle-grade mystery series that’s spooky, creepy, and filled with gothic twists! Meet the Sinister-Winterbottom twins, who solve mysteries at increasingly bizarre summer vacation destinations in the hopes of being reunited with their parents—or at the very least finally finding a good churro.

“An absolute delight. If I have to die in a waterpark, I want to die in this one.”—Holly Black, #1 New York Times bestselling author of The Cruel Prince

“Wickedly weird. . . . Will appeal to anyone who loved A Series of Unfortunate Events.” —The New York Times

Meet the Sinister-Winterbottoms: brave Theo, her timid twin, Alexander, and their older sister, Wil. They’re stuck for the summer with their Aunt Saffronia, who doesn’t know how often children need to eat and can’t use a smartphone, and whose feet never quite seem to touch the floor when she glides—er—walks.

When Aunt Saffronia suggests a week pass to the Fathoms of Fun Waterpark, they hastily agree. But the park is even stranger than Aunt Saffronia. The waterslides look like gray gargoyle tongues. The employees wear creepy black dresses and deliver ominous messages. An impossible figure is at the top of the slide tower, people are disappearing, and suspicious goo is seeping into the wave pool.

Something mysterious is happening at Fathoms of Fun, and it’s up to the twins to get to the bottom of it. The mystery, that is. NOT the wave pool. Definitely NOT the wave pool. But are Theo and Alexander out of their depth?