The Trap Door, by Lisa McMann (Scholastic, Feb. 2013), Dak, Sera, and Riq find themselves in 1850--and they know, from their study of history, that the Underground Railroad is doomed to failure, Abraham Lincoln isn't going to be president, and the Civil War is going to last for fifteen years... But they don't know that history should have happened any differently. And, as usual, they must make their way through the dangers of an unfamiliar time, not sure that the things they are changing really are what should be changed.
In this case, the dangerous for Riq are particularly high, as he is black. Almost immediately the threesome walk into a trap--what looked like a safe house turned out to be a snare. Riq is taken by slave traders...and Sera and Dak must try to find him. Things get complicated when Riq escapes, along with the woman who is his own ancestor, and he's faced with the horrible dilemma of letting her history happen as he knows it did, or trying to change it, and perhaps writing himself out of existence...
And working against the three time travellers are a rival organization of bad guys, who, for their own greedy purposes, don't want history fixed.
Although I wasn't sure I wanted to read another time travel book that would tell me about the evils of slavery, I soon realized that I didn't need to be worried. Because this is an alternate America, there was enough excitement from the differences to make it a fresh, fun, read. And it was really easy to cheer on Sera, Dak, and Riq as they revitalized the Underground Railroad and the Abolitionist Movement, paving the way for a shorter Civil War...It was also easy to cheer for Harriet Tubman as she took down bad guys with well-timed swings of shackle chains.
This was very much Riq's book. He's been something of a cipher in the previous installments, but here we see much more of his point of view, and he becomes a real person, which I appreciated. Dak, on the other hand, was rather annoying in this installment, but you can't win them all.
In short, another fun read in a series that should appeal lots to kids who like plenty of high stakes action and adventure, with lots of interesting alternate history twists. The violence is real, but not so much so as to make the books too much for their target audience.