Heart of Iron by Bec McMaster is a great addition to her London Steampunk series. It delves deeper into the world of the Echelon society and we learn more about the political workings/uprisings taking place. Will has been battling his attraction to Lena since he first met her and he is determined to keep his distance for her own safety. Lena, after having been rejected by Will has avoided him for the past couple of years, that is until fate and circumstances bring them together. 
 I really enjoyed Heart of Iron and reading along as Will and Lena navigated their feelings for each other. The story is intricate and weaves the characters together skillfully as events unfold. There is action, intrigue and danger. The chemistry between Will and Lena is intense yet their romance is quite sweet. Will is a wonderful hero. He is gruff, strong, protective and sweet. Lena is a good fit for him and I was happy to see that there was more to her then what was described in the first book. Heart of Iron is entertaining and well written. I look forward to future books by Bec McMasters. 
 Heart of Iron and the London Steampunk series is highly recommended.