(Image: AAP/Daniel Pockett)

Just when things seemed to be returning to normal, an alarming spike in coronavirus cases has hit Victoria.

With community transmission spreading through security guards, GP clinics and large family gatherings, the state is scrambling to get things back under control. 

Why did Victoria, a state which locked down harder and more cautiously than any other, get hit by a new spike? The answer could be down to changing behaviour as restrictions loosened, or sheer bad luck.