A zombie apocalypse hits ZooWorld on the busiest day, and the animals (and humans) find their friends and families torn apart - literally - by zombies. On this ill-fated day, Musang, an Asian Palm Civet sneaks into the Zoo to steal food but finds himself trapped amidst the zoo-pocalypse.

In the aftermath of the zombie outbreak, Musang meets Grace, a young rebellious flamingo, during a failed attempt to escape ZooWorld. Musang learns of the zoo animals’ detest for Outsiders and is almost outed as one before he is narrowly saved by Beatrice. Samba takes on Shubrah for the role of King of the Zoo and emerges victorious, promising to rebuild ZooWorld to its former glory.

It is the first day of Samba's reign as he sets down "Samba Rules" and puts the animals to work. The lions stumble upon the Animal Feed Centre, while Musang and Beatrice are forced to visit the dreaded Zoo Hospital. The animals capture a wild human and a zombie in Snowlandia to probe into the origins of the mystery outbreak.

When the sick and injured animals are forcefully quarantined, Shubrah is separated from her heavily pregnant daughter, Sita. As food supplies dwindle, Grace proposes to Samba the possibility of hunting and grazing outside the zoo. Back in Snowlandia, Grace and Musang stumble upon the zombies' kryptonite.

Things take a turn for the worse when Sita goes into labour, sparking a foolhardy attempt to break out of quarantine and seek help. Meanwhile, Sora and Sibo accidentally let in a pack of zombies, leading to the Second Massacre of the animals. Musang carries out a Pied Piper-esque plan.

With no end to the quarantine in sight, a livid Shubrah instigates Grace and Musang to overthrow Samba and the lions. The quarantine enclosure becomes a scene of murder, while Grace and Musang rally the troops. Shubrah makes an unexpected alliance but it is all too late. Sita dies in labor as Shubrah bears witness to a frightening revelation.