DEATH IN PARADISE, BBC1, 9pm

THE sixth series of the warm and sunny murder show begins.

The scientists at the Saint Marie Volcano Observatory are puzzled. Their sensors up on the mountain keep detecting movement. Is the volcano grumbling or perhaps it’s just a nocturnal animal nosing about? One of the scientists resolves to spend the night on the volcano to try to solve the puzzle.

When he doesn’t reappear the next morning, rescue teams are scrambled and his body is found high on the mountain.

Was it a heart attack? He was fond of the fags, after all. Or perhaps there was a particularly scary nocturnal animal up there? Or could it be murder?

But when DI Humphrey Goodwin is called to investigate, his suspicions fall on the dead scientist’s colleagues. Was he killed by a jealous academic who wants to be king of the mountain? If so, how did they get up there to murder him? Following him up the volcano would have involved hiking and supplies.

This is one of the cosier, less demanding crime dramas, but therein lies its appeal.

SPIES, C4, 9pm

“YOU don’t know our names. You don’t know what we look like. You don’t know what we do.”

This new reality gameshow says spies are at work every single day, not in secret corridors in Whitehall, but on the streets beside us. There is a “parallel universe” of intelligence activity happening around us constantly and we know nothing of it.

In this new series, a group of former spies, known as Control, are putting 15 ordinary folk through a course to see if they have the guile and courage needed to become a spy. But as the contestants try to prove their worth, they don’t know that one of their number is a mole who’s reporting on them to Control.

Can they keep their cool, like James Bond, or become a bunch of cry babies?