Senator Van Horn gets hit by a car and is taken to the hospital.  Newton shows up and tries to steal his body.  Broyles stops him just in time.  

Van Horn is a shapeshifter.  

Walter begins working on the shapeshifter because it is alive.  He wants to figure out who created it and what information it knows.  

Peter and Bolivia search Van Horn’s office and find a case containing information on all of the Fringe personnel.  

Newton gives Bolivia a hard time, telling her she is not fully committed to the task so she will fail.

Walter figures out a way to ask the shapeshifter questions, evoking an emotional response by simply showing it items which triggers neurological brain activity.  

They next bring in Van Horn's wife, hoping she can induce an emotional response and get him to answer questions. Walter has Patricia touch Van Horn, to help increase his neuron activity.  He then pops up and begins to recite numbers, linked to their upcoming wedding anniversary.  

Bolivia gets a text, warning her to leave the lab.  She gets Walter to take a break and get something to eat.  In the cafeteria line, Walter remembers a stegosaurus has a brain in its rear end and races back to the lab.  

Peter confesses to Bolivia that he feels she is a completely different person.

In the lab, Walter begins cutting into the shapeshifters back.  A police officer shapeshifter steals the computer chip and knocks Water unconscious.  

Newton kills the police shapeshifter because it has emotional ties to its human family.  Peter and Bolivia show up and begin pursuing Newton.  They apprehend Newton and Bolivia is able to get the disc without Peter seeing.  

Bolivia brings Newton a microchip in jail to help him self terminate.  

Bolivia has sex with Peter.