John Lutz: Nightlines (USA 2004)
From the Publisher:
A murderer is stalking the streets of the St. Louis, and the only connection between his victims are the nightlines-special phone lines used by the phone company to test equipment. At night, lonely people use them to make contact with each other: to talk, to meet, perhaps, to have someone who will care, even if just for a moment, anonymously. But something has gone horribly wrong, and people are dying. Private eye Alo Nudger is part of the network now, and he soon discovers the very special lure of the nightlines when he falls in love with a woman he meets over them-a woman who may be the next victim...
John Lutz: Nightlines. An Alo Nudger Mystery. iBooks; ISBN: 0743497899 (November, 2004), 288 p., $6.99.