Rivers of London: Here Be Dragons #4 — Ben Aaronovitch

CO-WRITTEN BY NEW YORK TIMES BEST SELLING AUTHOR, JAMES SWALLOW! A dangerous monster is at large above the streets of London. And its name... Wyvern! After a Met Police helicopter on night patrol is attacked by an unidentified aerial phenomena, the Met's only sanctioned wizard, Peter Grant, and his mentor, Thomas Nightingale, are called in to investigate.