The mud pit might be a different matter, although I vaguely remembered watching a science experiment on television involving a swimming pool and custard. At the time my focus had been on the poor sod who had to clean up the mess afterwards. However, there was something to be said for being a couch potato; that show might stand me in good stead now.

I decided to make a run for it. Counting under my breath I dashed across, picking up speed when I hit the mud to avoid sinking into it. It worked. The momentum – and something to do with the laws of physics – kept me going. I scampered across the surface, springing happily onto solid ground on the other side. That was how to do it.

I let out a crow of exultation then, remembering my promise to Barry, swivelled round to the three contestants who were still stuck and shouted, ‘In your face!’ It was mean and nasty and I felt more than a trickle of guilt but I needed to make sure I wasn’t thrown off the show.

Panting hard, and under no illusion about what Winter would say about my lack of fitness if he saw me now, I completed the last few obstacles. I was almost ready to collapse but I still had a way to go. I jogged forward, weaving in and out of the trees which I was sure had been placed there just to annoy me. I could see the Celtic-knot puzzle up ahead. Then a root came up out of nowhere and I went flying. Arse.

Heaving myself up and spitting out a mouthful of dirt, I ignored the cameras that were zooming in on my exasperated face and wiped my eyes. As I blinked away flecks of muck, something flitted across my peripheral vision. I half-turned, just in time to see something shoot behind one of the larger trees fifty metres or so away. It could have been an animal – but what it looked like was a human being with long straggly hair moving around on all fours.

I froze. Did I really just see that? I spun round towards the cameras but they were all pointed at me. Engaging the cameramen in conversation would be useless. First of all, they were under orders not to communicate; second, I reckoned I’d used up any goodwill I had with them. Another mutter about a hallucination and I’d be out on my ear.

Swallowing hard and trying to stay calm, I glanced back warily. There was no sign of any potential zombie. I edged to my right and peered round, catching a flash of dark clothing. Then there was a loud heaving grunt, not dissimilar to what I imagined a death rattle would sound like.

I raised my hands, ready to perform whatever defensive or offensive runes were required, when there was a ragged whoop from behind me. The zombie, if that’s what it was, rustled in alarm. I heard a single pant, like a breath, then the thing crashed away through the undergrowth. The three contestants who’d been stuck in the mud pit were oblivious. As they passed me, they continued to whoop, holding hands and beaming with muddy delight.