This is one of my favorite series.  I love klutzy, socially awkward Mira.  She's my hero. 

Mira and crotchety sidekick Mrs. Berns and stoner friend Shaggy...err...Jed...take off on a Valentine's Day themed train ride across the country.  Along the way, they encounter a murder, a disappearance, and a lot of cloak and dagger. 

This book was a downhill slalom of that hit a concrete wall at the bottom with a resounding OOOF! I can't remember the last time an ending to a book affected me so much.  I will be so bold as to rank it as probably the best book I read in 2015, just on the ending alone.

I highly recommend this series, each an enjoyable and quick read and always entertaining.