you come to a river separating two biomes.  

something doesn't look right.                                                                                                                                             
                             
                                                                                                                  
                                                                                                                                               
cross river                                                                                                                                               
                                                                                                                                               
jump into it                                                                                                                                         
                                                                                                                                               
                                                                                                                                                  
                                                                                                                                               
                            
                                                                                                                   
    O                                                                                                                                                
   /|\                                                                                                                                               
   / \                                                                                                                                               
                                                                                                                                               
          ~                                                                            ~                                                 ~        
                                                                                                                                               
    ~                                 ~                              ~           ~                                                                 
                                                                                                                                               
                                                                                                                  ~                             
                                                  ~                                                                                             
                  ~                                                                                  ~                                           
                                                                                                                        ~