The Lorgaire, or Detective, and Big Mac Giolla ar two very different people. Although the Lorgaire is a little fellow, according to himself he is a big detective - someone who detects big things. As for Big Mac Giolla, the Lorgaire thinks he would make a fine assistant - he could break a lock for him, carry big bags, or even frighten away rogues.

But now, as the land is threatened by a fierce dragon from the North, Big Mac Giolla is only worried about his stomach. And not only does the Detective have to convince his hungry friend to help him search for the dragon, but first they must battle against an assortment of rogues, and then banish this giant dragon from the country! Easier said than done!