Before the darkness when humans were around, The cave was a place where weapons were made. Each of them was one of many animals that were bred, modified and trained for certain jobs. Tag got free and saved the others.
The Ducks need the technology and weapons in the cave to help them to take over the world. But they don’t know where the cave is so they have to lure the team out in order to capture them and find it.
Tag and the team remember how badly they were treated and how many of their kind were killed before the darkness. They believe that everyone should live in peace. Nothing can be killed deliberately.