When a body is found stabbed to death at the far end of Baker Street tube station, it seems like an ordinary murder. The victim is an exchange student at Central St. Martins named James Gallagher and his father is an American senator. The Folly have been called in to assist with the investigation and it is quickly discovers that there is a supernatural component to this crime. This case leads Peter Grant into the secret underground that lies underneath the streets of London. 
 Peter Grant is back in the third book in the series, still a sorcerer's apprentice to Inspector Nightingale. The Folly, which is the police department that specialises in the supernatural has grown to three, as Lesley May officially joins the team. Yet again this is a natural progression in the series, Peter doesn't know many spells and still struggles with his form but he has grown as a police officer, a wizard and a person. What I enjoyed about Whispers Under Ground is the character Dr Abdul Haqq Walid is explored in greater detail. He is a world renowned gastroenterologist and cryptopathologist who works with the Folly and is investigating how magic effects the world. This allows Ben Aaronovitch to build his world a bit more and explores the effects of magic. 
 While this is an urban fantasy series, it follows the tropes found in a police procedural and Peter Grant never just relies on his magical abilities but rather sticks to his strengths, which he learned from his training. There is a lot of investigational work within the series and sometimes I worry that the police procedural elements will over power the urban fantasy or humour, however Aaronovitch gets the balance right. 
 If you have not read the series, I would highly recommend it mainly because of the character development, in particular Peter Grant and Nightingale. Peter Grant is a biracial character (his mother is from Sierra Leone and I am pretty sure his father is white) and his heritage and life play a big part in shaping him. This also allows Ben Aaronovitch to play a little with racism but I feel like he handles the whole subject well. Inspector Nightingale is a prim and proper Englishman and the last officially sanctioned English Wizard, having gone to a now defunct private school for wizardry allows for plenty of Harry Potter jokes. 
 This is a fun series that I am completely immersed in; when I finished Whispers Under Ground I didn't want to leave the world. I started Broken Homes (which is book four) straight away, which is unusual for me but I needed to know what happened next. For fans of urban fantasy, police procedurals and British humour, I highly recommend the Peter Grant series, I do not think you will be disappointed. 
 This review originally appeared on my blog; http://literary-exploration.com/2015/...