I read these about a year ago. Fever Crumb followed by Web of Air are a new series of books that prequel the Mortal Engines SciFi series and features an orphan (Fever) brought up by the kindly, but eccentric, Guild of Engineers in London of the far future.
Everything about Philip Reeve’s books is both original and entertaining and these are no exception. The books have got a bit of everything- action, mystery, science etc… all wrapped up in a peculiarly British flavoured diesel-punk setting. If you are old enough, you’ll get the “Skinner’s Union” reference.