Kate says

Undercurrent is a continuation of Vanessa’s story, girl who discovered being a modern siren and here a continuation is an accurate notion since the second part in Siren Series left me with the same emotions as the previous part Siren (review): little unsatisfied but still decent YA read.

Getting back to normal life Vanessa struggles with her new abilities and nuisances resulting from being not an ordinary human being. Not only physical inconveniences are on the spotlight but also (highlighted in this part) family matters, secrets, discoveries and unexpected answers to hidden questions - making the book rather a family story and romance than a suspense. With her head full of uncertainties she needs to find strength to fight back those who she thought were defeated but reborn want to hurt those who Vanessa cares about.

The book left me with no higher thoughts, however, it’s a fast and enjoyable one time read. The author is consistent with her style and characters build. The book construction is also parallel to the first part, leaving all dramatic events to the last pages.