4x8: Too Far Gone
After dealing with an strange flu, the group must face the real danger: the other human beings.
Too Far Gone is the mid-season finale and it features the great battle between The Governor and Rick's group. The episode starts with The Governor capturing both Michonne and Hershel and this is a clear leverage for the fight to come.
The negotiation starts when Rick goes outside of the prison as he realizes both Hershel and Michonne are now prisoners. The war is really close and Rick buys some time by telling the attackers they have a lot of ill and defenceless people. Meanwhile, Daryl gets all the military equipment and distributes it among the prison people.
The real battle starts when The Governor kills Hershel with Michonne's katana. After this terrific scene, gunshots start and there is no coming back to peace. Beth and Maggie burst into tears as her dad is now dead. Michonne finally kills The Governor and the group must now leave the prison as it isn't safe anymore. Judith is presumably dead and both Carl and Rick are devastated.
Interesting facts: "Too Far Gone" is a quote from the talk between The Governor and Rick previous to the battle. Carl's father thinks they're "not too far gone", but the contrary is proven. This is the only episode of the season with main characters deaths and of the few of the series that includes more than one major character dying. Finally, a young girl dies again in a mid-season finale: this is Meghan's time.