4.5 stars. 
 The Nightmare Garden is an outstanding sequel to The Iron Thorn that cleverly combines the magnificence of Lovecraft, Steampunk, and Fae into a dark and eerie world, which has an ambitious protagonist on an ambitious adventure to turn back time and make things right - the way they should have been in the first place years ago. This adventure-filled tale has twists, shocks, and surprises around every corner, and will leave you wanting the third book, The Mirrored Shard, to see how this trilogy ends. Caitlin Kittredge is an excellent world-builder; you will have no problem being immersed in this world. And if you enjoy Fae tales just as much as I do, then this is one to add to your reading lists. 
 In The Iron Thorn, Aoife destroys The Great Engine that runs Lovecraft and The Iron Lands. Although it was in herself to rebel against the rules and the society in which she was brought up in, it was Tremaine, a member of the Fey, who convinced her to believe in things - that were in actual fact false - ultimately leading to the destruction of the engine. Aoife didn't know that once she does that, she will wreak havoc upon The Iron Lands. A gateway opened between The Iron Lands and the Thorn (the fae land) consequently letting the creatures and monsters of the Fae world into the land of iron. 
 Aoife is troubled with guilt by what she has done, and so with Dean, Conrad, Cal, and Bethina they run. After returning to the destroyed and ghoul-infested Lovecraft in search for her mother Nerissa, Aoife and co. are saved by Archie Grayson, her father. Aoife begins to have nightmares, and after being told otherwise, she escapes to try and set things right in the world, pointing her to The Arctic Circle and the Nightmare Clock which is the key to turning back time and to undo the damage she has done, and also the damage from years ago involving her family. 
 Aoife is the Macbeth of this world. She is foolish and stubborn, which makes for an interesting protagonist who makes mistakes despite believing she is ultimately doing good. In The Iron Thorn she falls victim to Tremaine's lies - her first mistake. Now in this book, she makes more mistakes but with the knowledge and intention that something will come out of it, be it either good or bad. She regrets and realises her actions and decisions and therefore goes off to search for the Nightmare Clock. Now answer this: have you ever wished that you could turn back time and redo something because you made a mistake, or did something wrong and want to do it again to set things right again? On an exam? In a relationship? Anything? If yes - and I know there cannot simply be a no from anyone - then YOU my friend are no more different to Aoife than you first thought. She is a realistic teenager who just wants to do right and get what she wants and desires, even if that means putting herself in harm's way, so be it. Aoife is a tragic being, in a tragic world. 
 Caitlin Kittredge is flawless in her world-building - I could not see one weakness, one hole big or small, in this world of hers. It is so cleverly crafted and I just want more of it. I want more of this world. And with this world comes some amazing characters. We learn more about them and their pasts, their truths, their dreams, and their wishes. Not one is a flop. They each make this story worthwhile. And poor Cal, trying to hide his inner-ghoul, his natural state, in order to be with Bethina. Poor guy. There is also a great family theme that runs through - a family that has been dismantled and turned on it's head. And Aoife's motives are truly to bring her family back together again, even though her father has moved on with another woman. It is all very realistic. 
 If you enjoy a dense steampunk, fantasy, or something with Fae, then these are books you have got to pick up and read. You will not be disappointed. Trust me. And trust is something you should not give when you read. You'll never know who will use it against you.