I haven't met Sofia, but I can only assume she is cuter than Drew. 

  Once again, Bo is convincing, as always, in terms of the definition of a soul....not a supernatural being/entity, but the essence of one's individuality.  I think that is really what a 'soul' is as well.  
The Tom/Drew thing isn't too much of a mystery.  The marriage was, but he left her because she started dating chicks.  Not that I blame her 
