 Why did Frank make a phone call after shooting the client at the beginning of the story?
Therefore, it was with a mingled sense of excitement and satisfaction that he greeted the tall, dark, smooth-faced figure that came up the stairs and into the office shortly before noon. Opening the desk drawer, which was almost empty, Pembroke removed an automatic pistol fitted with a silencer. The series of events leading up to Pembroke's present occupation had commenced on a dismal, overcast evening in the South Pacific a year earlier. One in particular, an attractive woman of about thirty, tossed back her long, chestnut locks and gazed up intently at Pembroke as he passed. "Incidentally, just where are we, anyway? "Which way is it to San Francisco?" asked Pembroke.
 He wanted a call in a third party to take a look at his client.
 He needed to report the shooting to the police.  He wanted a call in a third party to take a look at his client.  He wanted to tell his partner that his newspaper at had worked.  He promised those in charge of him that he would report back every time he successfully made a kill.