My favorite author of nonfiction narrative will switch from past to present usually when he wants to bring the reader into the scene, especially if he is physically in the scene himself reporting as a journalist. I recently wrote something similar to the following, which didn't go over well with my friend, my "reviewer." "My girlfriend decided to fulfill a life-long dream of traveling to Australia while I had a work project scheduled in Chile. Upon my return from Chile, a couple of phone calls turned my temporary bachelor life upside down. My girlfriend's brother calls first -- Jen has not been heard from in several days and may be missing. What? Simple communication error, I think to myself. But as the days pass, the situation becomes dire."