What's an 11-year-old boy to do when an ugly dog called Blacky appears on his bed and tells him he has been given the mission to rescue God? When Marcus is woken by a dog going to the bathroom on his bed, he is understandably upset. And Blacky the dog has other surprises in store. Soon Marcus and his disruptive friend Dylan are on a mission to rescue God—a sick pygmy bearded dragon—from the local pet shop, but time is running out. To complicate things, Marcus' sister Rose is in the picture—she who thrives on terrorizing her little brother. She is the sister from hell, but revenge will be sweet—or so Marcus thinks.

A free trip to the Northern Territory! Sounds good, thinks Marcus—"Mucus" to his sister Rose. But when his best friend Dylan joins the family holiday, mayhem is not far away. Blacky the farting dog, back in his second adventure, has a mission that Marcus and Dylan can't refuse. Trouble is, this mission involves a monstrous saltwater crocodile who would much rather chomp on a human for dinner than have a civilized conversation. Of course, there's also the small matter of a giant big-game hunter on a collision course with our heroes. And will Marcus be any match for his mean older sister Rose and her lightsaber-wielding best friend Cy Ob Han? Blacky the master of disguise is back, full of attitude and smelly as ever.

A third wacky adventure with Blacky the farting dog—between giant bully boys, unintelligible Scottish camp instructors, and the need for thermal underwear, can the boys find the last remaining Tasmanian tiger? Blacky's back, smellier than ever, and he's got a new mission for Marcus and track down the very last Tassie tiger and save it from extinction. Simple, really. But throw in some bumbling thylacine hunters, a bully out to get you, a hairy Scotsman on your trail, and anything can—and will—happen. Especially as time is running out.