Terrible script, terrible CGI and terrible acting. Zoo should have ended on season two. However, the writers and creators decided to continue with it, at any cost, and by bringing back characters that were supposed to be gone for good.
Just like the first season, Zoo's second season script felt rushed and with plenty of inconsistencies. At times it's fun enough to keep you watching, just to see how the characters are going to solve each problem they find on their way.