Sir Trevor McDonald is travelling the length of the Mississippi River. The wrong way round.
Think about it. If you were going to explore the Mississippi, you would start at its source, right? You would begin with a tiny stream in upstate Minnesota, and then watch as it grew and grew, and the US grew around it.
But no one asked me. And so Sir Trevor is beginning his three-part, 2,500-mile ITV1 journey, The Mighty Mississippi with Trevor McDonald, at the Gulf of Mexico.
"It's the auspicious start of America's most commercial waterway," he says, as he flies over the delta. "No it's not," I tell the screen. "It's the auspicious end. You're doing this the wrong way round." The screen ignores me.
Travelling through Louisiana, Sir Trevor takes a whistle-stop tour of Deep South cliches. Privileged debutante with a wardrobe of white dresses: check. Jazz club: check. Here, he fails to play the sousaphone. This is mildly amusing.
Jazz funeral: check. "A marvellous way to celebrate the end of a highly regarded life," says Sir Trevor. He has the manner of an elderly tourist, who knows that travel broadens the mind but actually wishes he was back in the Home Counties, reading The Times.
This proves a problem. He does not joke. He does not engage charmingly with the locals. He does not ask the questions viewers want asked. "We call this the crumb-catcher dress," says the debutante, as she takes Sir Trev on a tour of her wardrobe. "OK," he replies.
He perks up, however, when he is actually allowed to do what he clearly wants to be doing: discussing current events. There is a moving segment in which he tours the ninth ward of New Orleans, effectively a ghost town since Hurricane Katrina. Each empty house is marked with a cluster of numbers, indicating the date it was inspected and the number of dead bodies found inside.
Sir Trevor provides the harrowing facts, the sobering context - the news report. His guide, Darin, meanwhile, provides the colour. "She's my oldest neighbour," says Darin, as he drives past an elderly woman. "Every Christmas since I was a little boy, that lady has bought me socks and underwear."
Sir Trevor is better, too, when discussing the South's inescapable past. He is clearly shaken by his tour of the cabins where slaves were housed - "kept" would be more accurate - on a pre-civil war plantation. And liberation, he points out, was only the start of the journey from slavery to civil rights.
"Aha!" I say to my still-unresponsive screen. Martin Luther King Jr was killed in Memphis. Memphis is further upriver than Deep South plantation-land. Maybe someone has thought about the order of things, after all.
The Mighty Mississippi, ITV1, 9pm, Tuesdays until 24 April.