Scholastic Press
The third book in the Infinity Ring series is "The Trap Door" by Lisa McMann.

"INFINITY RING, No. 3: The Trap Door," by Lisa McMann, Scholastic Press, $12.99, 190 pages (f) (8 and up)

“The Trap Door” is the third in the seven “Infinity Ring” series where previously the three young Hystorians have been in Medieval France, captured by Vikings and now seek the help of the Infinity Ring, which is programmed to assist a leap in time and place.

Dak, Sera and Riq time-warp from Washington, D.C., after fixing a history Break or mistake in the life of first lady Dolley Madison and find themselves in Maryland in the year 1850.

The three are held hostage by a fake abolitionist, and then realize their mission is to aid in the efforts of the Underground Railroad. Riq is captured, shackled and put up for slave auction with a young woman and her two children. He recalls (a Remnant) the time when his great-great-great grandmother was similarly auctioned and realizes he is reliving that scene “living in his ancestor’s shoes.”

Sera and Dak work against the troops to find Riq and meet a publisher and true abolitionists, Harriet Tubman and John Bowley, who are tireless in supporting the Fugitive Slave Act.

“The Trap Door” is packed with thrilling escapades: slave chasers, bloodhounds, hiding places for slaves and near drowning. Author Lisa McMann adds another layer of interest as Riq discovers what may be his own ancestral line among the fleeing slaves.

While each of the books in the “Infinity Ring” series stands alone as a middle-grade adventure and it written by a different author, McMann has left some seams showing where two vital themes proposed in the first book, “A Mutiny in Time,” are not further developed in “The Trap Door.”

In “A Mutiny in Time,” besides the adventures of the three young Hystorians, one of their goals is to find Dak’s missing parents who are lost in time and space. This crucial project is not mentioned in “The Trap Door.” Nor is an implicit theme for the entire series that all of history — timelines, facts and people — will have perpetual shifts when the mistakes or Breaks in history are changed since the Infinity Ring does not just afford time travel, but also alters the infinite future. Intuitive readers may realize this, but the author has not included it as a thread throughout the story or as a problematic issue for the enterprising protagonists.

Included in each book in the “Infinity Ring” series is a Hystorian Guide with maps linked to 3D games. Also, readers are introduced to the next time travel for the young Hystorians, which will be the time and location of the Mayans in “Curse of the Ancients.” See for more about the series.