“Perfectly good device in industry.”

That was Pete Knight’s assessment of Paul’s Kong descender. Underground, on a caving rope, during Dean’s first ever trip as an SRT leader, it had one setting: stationary.

Merlin Mine sits off the road between Stoney Middleton and Eyam. Five minutes from car to cave. A pitch kind enough to run laps on, because you can walk out the top, loop around the hillside, and come back down again. Dean had rigged it. Paul clipped on, pulled the handle, and went nowhere.

The Kong has an anti-panic feature that locks the rope if you squeeze too hard. Brilliant on thin industrial ropes. On caving ropes, the gap between “locked” and “moving” is somewhere between tiny and imaginary. Paul found it once. Then it vanished.

Dean, twenty minutes into his first SRT lead, talked Paul through a changeover mid-pitch. Swapped him onto a standard stop descender. Paul was at the bottom in seconds.

Mark, who does rope access for a living, then asked to try the Kong on his way down. He lasted about thirty seconds. When it did get going, the rope juddered through the device with a dong-dong-dong that echoed up the shaft before the whole thing locked up again. At one point he was pulling with both hands. His verdict: “I wouldn’t use it.”

It’s a Kong, not some no-name bit of kit. “It just doesn’t work for caving” was the diplomatic version. Paul is getting a red handle stop. The Kong’s future is as a doorstop, or a very heavy paperweight.

But the descender drama was just the warm-up act. Merlin Mine is small and everything sits close together, old lead workings mixed in with natural cave in ways that catch you off guard. In one passage, Tim pointed at loose rock overhead. “Stuff like that is called hanging death. Just to make you feel happier.” The compacted mud on the floor suggested nothing had dropped in a while. Reassuring, in a way.

Round a corner, stone stemples wedge overhead, holding up whatever’s above them through something between engineering and optimism. Then scalloped rock and a small pool that look like they belong in a different cave. “This is probably the prettiest bit in the whole of this cave.” A pause. “I realise that’s not very much.”

At a crossroads where passages split in four directions, the philosophy was simple: every hole is a goal. Dean sent people off exploring. Not all the holes cooperated.

The main event was a low crawl leading to an SRT pitch called Laxative Pot. Mark, Paul went through. Oana, still processing Sidetrack from a few days earlier, stayed behind with Tim and Dean.

Mark came back. “It was well worth it.”

Paul: “That’s the highlight. Now that it’s done.”

Dean found tree roots growing down through the mine ceiling. Tim asked if he’d recommend them. “No.”

Paul tried a foot ascender for the first time, working out that your left leg goes up before your right. Oana scrambled through the horizontal sections with Dean as a handhold on the trickier climbs. Between the pitch, the crawl, the exploring, two descenders, and a foot ascender, the group covered a lot of ground in a very small space.

At the car park, Paul summed up the evening: “I learnt a lot. I just enjoy doing all of it.”

This was Dean’s first lead as an SRT leader. He rigged the pitch, diagnosed a descender problem, coached a changeover mid-rope, navigated a mine he’d been into once before, and brought everyone out grinning. Which sounds like a successful night out!