 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. 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. "Your bet's as good as mine," said Pembroke. Spencer opened his mouth to protest, but saw with amazement that it was exactly this that Valencia was seeking.
 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.