Blood Son (3) by Erica Orloff finds professor Elizabeth Martin braving the dark world of vampires and dhampirs (half-vampires) in search of her missing twin, David. As she frantically searches Prague, Lizzie is forced to hire help in the form of Josef, a dhampir with an agenda of his own. Hot on David's trail, Lizzie and Josef also find themselves passionately in love. Will Lizzie's love be the redemptive potion that will save them all, or will the danger that follows Josef destroy them? It's an interesting premise, although the dark subject matter ultimately overpowers the romance between Lizzie and Josef.