After everyone finds Lyman, he tells them his story of how he disappeared as well as that of the Zabadu. Meanwhile, Dirk Dinkum is determined to get the Zabadu, regardless of whether the creature is real or not.
Lyman reveals that the Zabadu that rescued him was actually a man in a suit, named Dr. Sam. They ended up living together with the animals and protecting them. Dr. Sam then passed away and Lyman took his place. Lyman was unable to contact anyone due to the lack of working phones or a mail service.
As Garfield and Odie get snacks from Angie’s car, Lyman demonstrates his ability to scare hunters with the Zabadu disguise to Jon and Angie. But Dirk takes pictures of Lyman in the suit, planning to make it look like the real Zabadu is attacking them. Garfield and Odie discover Dirk and Buckley’s car and go back to warn the others. As Dirk and Buckley are about to leave, Odie interferes by attacking Dirk. Garfield takes the camera and runs.
Jon, Lyman and Angie want to know what’s going on. Dirk and Buckley chase Garfield in their car. Odie leads the other three where Garfield, Dirk and Buckley are heading. Garfield manages to dodge them and the two run into a cave. They think they have him trapped, but they encounter a bear that chases them. Dirk takes the camera back from Garfield and thinks he has won. They then hear a roar after which the real Zabadu arrives. Dirk and Buckley think it's Lyman, but Garfield points to where Lyman is located. The Zabadu then goes for Dirk and Buckley and throws their car away. Everyone celebrates the defeat of Dirk and Buckley.
As everyone prepares to head home, Lyman has Odie stay with him, pointing out that he is Odie's original owner. Garfield attempts to be optimistic and reassuring to Odie about this situation, then unexpectedly breaks down in tears and cries into Jon's leg. Garfield and Jon are very sad and say goodbye to Odie before he leaves with Lyman. Angie asks them to keep in touch with her. Jon and Garfield arrive home, still sad about the absence of Odie. Squeak and the other mice sympathize with them. Garfield remembers the good times he had with Odie and misses having him around.
When the doorbell rings, Jon answers it and is surprised yet delighted to see Lyman and Odie at the door. Odie heads over to a sad Garfield, who is happy to see him again. Lyman explains to Jon that after seeing how sad Odie was without Jon and Garfield, he ultimately decided that Odie was better off staying with them. After Jon offers to let Lyman stay with them, Lyman explains that he is needed more in Australia due to his job. He promises to find a temporary Zabadu so that he can visit once in a while. Everything wraps up with Garfield throwing the stick and Odie fetching it while Jon and Lyman watch their pets play.