(4) 4-6 Missing series. The focus here is on Jordan, series protagonist Jonah's understandably perplexed twin whose timeline only recently merged with Jonah's. The twins and their sister Katherine help bring far-fetched resolutions to ever-more-complicated paradoxes, including the "un-aging" of dozens of adults. There's no room for the historical exploration that characterized the previous volumes, but mind-benders abound, and this series-ender offers some glimpses into the future.

Reviewer: Shoshana Flax

(4) 4-6 Missing series. Charles Lindbergh kidnaps Jonah's sister Katherine as the surrounding adults are "un-aged" to thirteen. This seventh installment jumps in and out of the story of Lindbergh's son's kidnapping and sometimes bends the rules of the series' internal logic; but it also answers many of the series' big questions, including that of Jonah's original identity. A thorough author's note provides historical context.

Reviewer: Shoshana Flax

(4) 4-6 Missing series. Time-travel trickery lands Jonah, Katherine, and Chip in Russia before the Romanovs' assassination, along with Gavin and Daniella, who are actually the royal children Alexei and Anastasia. Between the complexity and violence of the historical moment and the usual matters of time-travel logic and ethics, this installment takes on too much, but it should be a welcome addition for series fans.

Reviewer: Shoshana Flax

(3) 4-6 Missing series. After time freezes in the present day, Jonah and Katherine travel to 1903 to return Albert Einstein's daughter Lieserl to her proper place in time. But Einstein's wife Mileva catches onto the time-travel principles and uses them to manipulate history. As usual, this series humanizes historical figures while providing plenty of action. Haddix elucidates the historical background in her author's note.

Reviewer: Shoshana Flax

(3) 4-6 Missing series. Jonah and Katherine travel to Henry Hudson's ship in 1611. There they must stop unethical time-traveler Second from changing history and thus ending the world. The text makes both history and time logic accessible and exciting. Haddix's usual thorough and engaging backmatter sheds more light on the historical mysteries of Hudson's last voyage.

Reviewer: Shoshana Flax

(3) 4-6 Missing series. Jonah and Katherine (Found, Sent) time-travel to Roanoke to restore Andrea to her original identity as Virginia Dare. But sabotage lands them in an unknown year, and they find themselves unsure if it's best to live out events as they first occurred. As the text raises worthwhile questions about the nature of historical record, the characters lend emotional depth to the past.

Reviewer: Shoshana Flax

(4) 4-6 Missing series. Jonah and Chip (Found) time-travel to 1483 Great Britain. Their task is to repair the rift caused when Chip and his brother (who are really the princes that King Richard III imprisoned in the Tower of London) disappeared. The time-paradox logic is shaky, but the taut pacing and many ongoing mysteries will engage readers willing to just go with it all.

Reviewer: Claire E. Gross

(3) 4-6 Missing series. Thirteen-year-old Jonah has always known he's adopted; Chip learns of his adoption when both friends start receiving threatening letters labeling them "the missing." Investigating, the two discover an inter-temporal child-smuggling conflict, both sides of which are out to get them. The fascinating premise of this series opener, buoyed by Haddix's usual likable characters and fast-paced writing, is loaded with possibilities.

Reviewer: Claire E. Gross

(2) 4-6 Missing Link Trilogy series. Christie and his newfound family of humans, talking animals, and human-animal hybrids in Fourth World struggle to understand the purpose of a sinister invader; meanwhile, an interwoven narrative follows new characters Nessa and Farral, whose societies are threatened by war. As in the previous volumes, the characters are sympathetic, the narrative tension is thick, and the moral ambiguities are profound.

Reviewer: Vicky Smith | Horn Book Magazine Issue: January, 2008

(2) 4-6 Missing Link Trilogy series. Human-animal genetic manipulation is the motor that drives this gripping book in a promising science fiction trilogy. Christie, thirteen, and his physically awkward stepbrother, Danny, travel to Fourth World, Danny's mysterious mother's home in Scotland. The tale unfolds quickly as the stepbrothers, an angry homeless girl, a talking sheepdog, and a starling make their way across Britain, experiencing natural and human peril.

Reviewer: Vicky Smith | Horn Book Magazine Issue: May, 2005