Complete story — includes the ending
As the citizens begin to exhibit psychopathic behaviors due to the infection, Fish kidnaps Strange and manages to find the antidote, but she is murdered by Gordon and the antidote is destroyed. A mourning Cobblepot is arrested by the GCPD after being attacked by the League of Shadows. Nygma and Barbara have Tetch, whose blood is needed to formulate an antidote, kidnapped during transfer. They contact city hall and demand a large ransom in exchange for Tetch. However, Gordon secretly contacts Nygma and arranges a deal to trade merely Cobblepot for Tetch. Bruce escapes from police custody when they are overwhelmed by the infected and seeks out the Demon's Head, a.k.a. Ra's Al Ghul, the leader of the League. Ra's has Bruce prove his worth by impaling Alfred with a sword.
Sources and content license
Source and revision history · Adapted from Wikipedia contributors, Gotham season 3. HTML formatting and reference markers removed. · Content license