 Why does the narrator make a phone call before explaining the bomb to Julia?
I had finished reading the Chronicle , folded and put it beside me, turned and looked out the window, expecting to see the San Joaquin Valley but finding only a sea of clouds instead. So I returned my attention to the inside of the plane, to the overstuffed gray-haired woman asleep beside me, to the backs of heads in seats before me, across the aisle to other heads, and down to the blonde. I learned the wisdom of keeping my mouth shut in the fourth grade when Miss Winters, a stern, white-haired disciplinarian, ordered me to eat my sack lunch in the classroom with her instead of outside with some of the other kids. This being earlier than I usually get up, it seems all I did during the night was feel my way past the escapement and balance wheel to see where the notch for the alarm was. One went to a battery and the other to hard round cylinders taped together. Quickly I went up past the train of gears to the alarm wheel. If this was anything like my own alarm clock, this one had something like ten minutes to go. It was forty minutes to Burbank and Lockheed Air Terminal. No, none of them would know it was there. We'd be leaving the valley for the mountain range north of Los Angeles soon, if we hadn't left it already. I tried to close everything off—the throb of engines, the rush of air, the woman sipping coffee noisily beside me—and I went into the clock and surrounded the seesawing wheel.
 The narrator fakes making a phone call so that he can focus on stopping the bomb again.
 The narrator needs to call airport security so that they can evacuate the area before he explains the situation to Julia.  The narrator needs to call the FBI and report the bomb before he explains the situation to Julia.  The narrator fakes making a phone call so that he can focus on stopping the bomb again.  The narrator needs to alert the bomb squad before he explains the situation to Julia.