This is a series.
The Bat is a 1997 crime novel by Norwegian writer Jo Nesbø, the first in the Harry Hole series.
Follows Harry Hole's efforts to solve the murder of a television celebrity whose demise is linked to a string of serial killings.
Inspector Harry Hole of the Oslo Crime Squad is dispatched to Sydney to observe a murder case. Harry is free to offer assistance, but he has firm instructions to stay out of trouble. The victim is a Norwegian woman who is a minor celebrity back home. Harry befriends one of the lead detectives, and one of the witnesses, as he is drawn deeper into the case. Together, they discover that this is only the latest in a string of unsolved murders, and the pattern points toward a psychopath working his way across the country.