Moonlocket is the sequel to the adventurous Cogheart. A story where a young girl, Lily, discovers the accident that killed her mother should have killed her too but her father replaced her heart with that of a cogheart; a perpetual motion machine. This one focuses on her stalwart friend Robert. After the death of his father he was taken in by Lily, her father, and their peculiar family of mechanicals. Lily's father a brilliant and famous mechanist was friends with Robert's dad and promised Robert he would teach him everything. Still recovering from the death of his father Robert still occasionally visits his old home. His most recent late night visit he finds something of his mother's and he gets put on the path of family he never knew and just maybe a mother who isn't dead. Robert, Lily, and the mechanical fox Malkin set off on another adventure to find Robert's mom and out smart the criminal Jack of Diamonds.
Overall, this was a brilliant follow up to the first book. Lily and Robert make a new friend, Tolly, and we see old friends too like Anna and Inspector Fisk. I loved the story I love how it expanded on Robert's character and it brought him closer to Lily and her Father. This can be read as a stand alone.
Book Three of the Cogheart Adventure. Once again Lily is the focus of this story but in this one she discovers more about her mother that she ever knew before. Like how her mother studied flyology and learning how to fly. It's Lily's 14th birthday and while is bound to be better than last years birthday debacle it seems that her father has forgotten it's her birthday in all the excitement of getting some award. Lily was soon distracted by the anonymous gift that was left for her, her mother's old diary with a flyer for Skycircus and VIP tickets. On the flyer was a drawing of a young girl with wings and from what she read in her mother's journal she thought this winged girl might have information on her mother. So grabbing Robert, Malkin and the visiting Tolly they ditch her father's stuffy dinner party and run off to see the circus. It wasn't what they expected. The ringmasters exploited the hybrids and treated them like freaks and in the end kidnapped Lily, Robert and Malkin leaving Tolly to run to safety and tell her father what happened. Someone from Lily's past is back and is out to make a quick buck exposing Lily for what she is a hybrid. It's up to Lily, Robert, and Malkin to escape and free the circus folk from the prison that has become of their circus.
Overall, another outstanding book for the series and it can be read as a stand alone but I would recommend at least reading Cogheart first, which is where Lily's story starts. These are wonderfully written books with grand adventures and characters that have you rooting for them the whole time.