RADIO CHOICE

JANE’S blood turns to ice as she sees the face of a man who, five years ago, violently attacked her. She accuses him, but he denies it, and Jane has in the past mistakenly identified another man as the attacker. Lyndsey Marshal (pictured), Graeme Hawley and Will Ash star in WHEN LAST I SAW YOU (RADIO 4, 2.15PM), a tense, troubling, high-calibre drama by Peter Whalley.

THE Government has promised a massive building programme to create 300,000 new houses a year. That can’t be done without churning up open spaces, destroying trees and plants and threatening our already fragile wildlife. For this week’s COSTING THE EARTH (RADIO 4, 3.30PM), Tom Heap asks if these new houses can be put up, quickly and cheaply, without destroying Green Belt land.

THOUSANDS of starlings swoop through the sky, heading one way. Then, in the blink of an eye, they veer off in a different direction. Their spectacular sky shows

— known as murmurations — are a source of wonder. How do these thousands of birds, without any obvious sign of communication, arrive so quickly at their collective decision?

FREE THINKING FESTIVAL (RADIO 3, 10PM) joins a panel of scientists as they look at the mysterious ways that flocks of birds, schools of fish, atomic particles and other seemingly separate entities can act as one.