Sentence 1: Sean was at work one morning. 
 Sentence 3: He introduced the new coworker, Jenna 
 Sentence 4:  Sean actually recognized her from back when they went to school 
 Sentence 5:  The two reconnected throughout the day and planned to hang out more 
 Option 1: Sean's boss said that his new boss would be Jenna. 
 Option 2: His boss announced that a new person had joined the team.