Resident Evil 4 Spoiler Free Walkthrough

 _ 
|_) esident Evil 4 /---------------------------------------------------------o
| \-------o--------\                    Capture Luis Sera                    |
       (0100D)      \--------------------------------------------------------o

I have confirmation that Sera has entered the castle.  Why would he return 
during his escape leaves me to question his motives.  But we must seize this 
moment to capture him.  We will get the other two Americans after we apprehend 
Sera.  It appears he took some vaccines when he stole our "sample.'  The 
vaccines we can do without but we must retrieve the "sample" for it is our 
life blood.  I feel there is somebody else or some other group involved in 
this whole affair.  If the "sample" were to get into the hands of that other 
entity, the world which we seek to create will not come.  We must apprehend 
Sera as quickly as possible.