This is the first in the Mysterious Detective Mystery Series.  Rachel Goodman is the writer of a mystery series with a sleuth, Duffy Madison.  Out of the blue she gets a call from a man claiming to be Duffy Madison, not just sharing a name with her character, but actually being her character brought to life.  He brings her news of a serial killer targeting writers, including one Rachel knows.

Duffy drags a somewhat reluctant and disbelieving Rachel along for the ride, a ride that ends up making Rachel a target of the killer.  Fun, cozy mystery with interesting insights into the writing life.