A virus can shut down a city, yet on its own it can do almost nothing at all — it can't grow, can't feed, can't even reproduce without hijacking a living cell. This episode asks what viruses actually are, and why they sit so awkwardly on the boundary between the living and the non-living.

You'll come away understanding how a virus is built, how it hijacks your cells to copy itself, why scientists still argue over whether viruses are truly alive, and the surprising ways they have shaped all of life.

Talking Science is sponsored by Kinsoft. Visit www.kinsoft.com.au

Further reading: Nature Education – "Viruses"; WHO – disease fact sheets; Carl Zimmer, *A Planet of Viruses*.