Before Totter's Yard, before Ian Chesterton and Barbara Wright, before the Chameleon Circuit was broken... the Doctor and Susan travelled alone.

The planet Quinnis in the Fourth Universe appears, at first glance, to be an agreeable, exotic refuge for the two travellers. But the world is experiencing a terrible drought, and the Doctor becomes its unwilling rainmaker.

Meanwhile, Susan makes an ally in a young girl called Meedla. But friends are not always what they appear, and the long-awaited rain isn't necessarily good news...