The Card by Jim Devitt

Van Stone is a lucky high-school student.  He has just landed his dream job as a batboy for his beloved Oakland A's baseball team.  As he gets ready for his first day at work, his dad, who is a research scientist and often away, makes amends by giving him a baseball card.  It is not the card of one of baseball's superstars but of a player who had a pedestrian career.  Van doesn't care, he loves his dad and treasures his gift.

Everything changes for Van overnight.  His dad is killed in a car accident.  Now Van is the man of the family and responsible for taking care of his mom.  Strange things begin happening.  Van starts to notice men in dark suits following him and his friends.

The suspense ramps up when Van gets a demand.  To keep his mom and friends safe, he must give up the card his dad gave him.  Why would anyone want that card?  The pace accelerates as Van attempts to evade his pursuers and keep those he loves safe.  Is there anyone he can trust to help?

Jim Devitt has written an interesting mystery.  The readers learns about the inner workings of a baseball clubhouse and also something of the biotechnology industry along with the mystery.  This book is recommended for mystery lovers but will also appeal to sports fans.