ENDEAVOUR, STV, 8pm

IMAGES of water stream across the screen in the opening segment: a woman dips her fingers in holy water, people relax in a steam room or frolic in a swimming pool, and water is used to create haunting music on glass tubes.

This collection of scenes foreshadows the murder in tonight’s new series.

Shaun Evans returns as Endeavour, the young Inspector Morse, and he’s called upon to investigate the death of a brilliant scientist, Professor Neilson, who has drowned. He had been at the peak of his career, and was working on a new computer or, as they were called in the 1950s, “a thinking machine.”

There had been lots of publicity about the professor’s work as the computer was being pitted against humans in a game of chess.

While some are keen to call his drowning a suicide, Endeavour thinks differently and his suspicions are confirmed when more bodies are found in the water.

But perhaps this new-fangled thinking machine might be able to assist young Endeavour in the investigation.

WALKING THE AMERICAS, C4, 8pm

WE’RE besieged by exotic nature and travel series at the moment. Perhaps they’re wisely scheduled for this time of year as the TV bods know this is the period when we all trudge back to work in the January rain thinking wistfully of summer holidays. BBC2 are showing us Thailand tonight at 9pm as “Earth’s tropical paradise”

but I’m preferring this new four-part series which sends a tough former paratrooper, Levison Wood, on a trek through the dangerous terrain of Central America.

He’ll be covering nearly 2000 miles as he journeys from Mexico to Colombia, and tonight he starts on the roasting Yucatan peninsula where he and his guide stop to explore the remains of the Mayan civilisation.

Moving on to Guatemala, they find themselves in lawless territory which is known for its cocaine trafficking.

The series is a combination of travel, history and a bit of a how-to guide for surviving in the wild.