In the middle of the night a stolen car has been set fire and left at a train station. Police dog Edge must find the offenders scent hidden under the smoke at the scene. Born too big to walk, puppy Quinn has shed some weight and is now ready to see if he’s got what it takes to become a police dog. Constable Brad Forster and police dog Edge track suspects to a nearby university, but it’s an enormous building and extremely difficult for Edge to find them with thousands of people having recently left the campus. Officers discover a car with four young men suspected of smoking cannabis in their car. They deny they’ve got any drugs so it’s up to Police dog Zac to find out if they’re lying.