Like Emma likes to exclaim....Ohmysweetgoodness!!! You cannot believe how incredibly good Of Poseidon is!!! So. i just re-read Of Poseidon(because its just that good, that you wanna go over it again and again and again.LOL) and the ending just gets me every time!!!...How can Anna Banks leave us with such a cliffhanger??? I CANNOT WAIT for the sequel!!!...Thankfully Anna won't leave us hanging for too long and we'll soon get to read Legacy Lost, the prequel to Of Poseidon, which tells you Grom and Nalia's story. 
 (view spoiler)[Grom is Galen's (Emma's love interest) older brother who is now king (in present time of the book). Nalia used to be engaged to Grom (way back before the book begins or before most of the characters in this book were born) and both were apparently much in love, but right before the wedding some kind of explosion happened and Nalia was 'believed' to have perished. Leaving Grom distraught but still he is very much in love with her after so many years. Towards the end of the book we learn that Emma's mom is really Nalia who has been hiding from the syrena all this time. (hide spoiler)].