2.5 stars.
I think the letter device worked better with the two of them on separate adventures - having Kate and Cecy directly corresponding was more fun and personal. In this one it felt more imbalanced, since Kate had a personal journal where she tended to talk about intimate moments with Thomas, and Cecy had a deposition. The plot dragged, not really picking up until the end, and I feel like both the cousins' relationship and the romantic relationships fared better in the first book.