 Why does Pembrook shoot the man in the corner?
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. Standing on the forward deck, Pembroke was one of the first to perceive the peculiar odor and to spot the immense gray hulk wallowing in the murky distance. Lacking such loyalties, Pembroke adapted quickly to the situation in which he found himself when he regained consciousness. One in particular, an attractive woman of about thirty, tossed back her long, chestnut locks and gazed up intently at Pembroke as he passed. "You're not casual enough, for one thing," said Pembroke, deciding to play along with her for the moment.
 The man in the corner is an android sent by alien masters to facilitate an invasion of Earth.
 The man in the corner is one of the strangers.  The man in the corner is an android sent by alien masters to facilitate an invasion of Earth.  The man in the corner was an alien invader.  The man in the corner came to kill Pembrook.