The Obsidian Compass (Time Castaways #2), by Liesl Shurtliff, for Time Slip Tuesday

The Obsidian Compass, by Liesl Shurtliff (middle grade, Katherine Tegan Books, Oct 2019) continues the time travelling adventures of three siblings adventuring through time that began with The Mona Lisa Key (link goes to my review).  That first book ended with Mateo, Ruby, and Corey getting home again safely, after many dangerous and difficulties aboard a time travelling ship captained by a ruthless man who was trying to use Matteo, in particular, for his own selfish purposes. But getting home safe wasn't to be the end of their time travelling.  Mateo needs to find his friend, Jia, one of Captain Vincent's crew, who was in danger of being dumped somewhere in time by the captain after she crossed him to help Mateo and his siblings.  Captain Vincent still has the obsidian compass that allows him to time travel, so Mateo decides to try to make his own, and against all odds, he succeeds.  But when he starts using it, he gets his family snarled anew in danger.

As they journey through time and space (in an old VW minibus), Mat realizes that saving Jia isn't enough; Captain Vincent needs to be stripped of his power in order for Matt's family to be safe.  Family secrets are revealed that make Matt question his relationship with his mother in particular--she once controlled the obsidian compass, with Vincent as her partner, and before she even adopted him, she knew a Mateo would play a role in the quest for something even more valuable than time travel--the promise of eternal life....

Parents are often missing in middle grade fantasy, so it's a change that both of Matt's parents are along for the adventure, and care deeply about keeping him and his siblings safe.  The twist about his mother's past, though, keeps her from smothering her son's adventures...instead, the reader, and Matt himself, aren't always sure about her motivations.....

There's not as much wild time travel bouncing from place to place here as there was in the first book--the plot hones in much more sharply on Matt's journey of discovery, and the choices he has to make.  There's still plenty of excitement, though, and an entertaining cast of supporting characters helps make the pages turn quickly.  The final third of the book, especially, is fast reading!

Unanswered questions remain, leaving readers anxious for book three!

short answer--not entirely my cup of tea, but I enjoyed this one more than the first book--I liked that there was more focus on character, and less galivanting....

I'm counting this one as a diverse fantasy--Mateo is adopted from Columbia.