In the book, he's referred to as Mr. Keating - 'Oh Captain, my Captain.'
   
Stranger number three is a passionate father, husband and teacher.  One of the things he loves most about the job is the 'a-ha' moments he sees in the young people he educates.  But one of his greatest fears is people seeing that he's not reached his own potential in life. 

What is potential anyway? The Krause trio dives into that question, touching on the highs and lows of expectations versus potential, the potential we see in ourselves versus the potential others see in us, whether there's a cap on potential, how we might calculate it... and more. 

The team has covered three of 52 strangers, and they're starting to catch their stride.