Darren's question, from a dark corner of the huge cave, was a little unexpected: "Anyone here like music?"
By way of explanation he turned his lamp on to a row of stalactites hanging from the ceiling, like a set of stone chimes, and hit a couple with a broken off length of stone. The result was a surprisingly musical sound. "This," he said, "is our xylophone. We need someone to play it."
A young woman took up the challenge, tapped away at the stalactites and produced what was almost a tune. The rest of us followed suit with varying degrees of musicality.
This recital took place some distance underground in Ulupaka Cave, near the village of Lakepa, on the island of Niue.
As its nickname - The Rock - suggests, Niue is a huge uplifted chunk of coral and it is full of caves. Visitors as far back as Captain James Cook in 1774 noted the number of caves around the coast and locals still use some for storing canoes. But there are also lots of caves inland, many of them quite extensive, and it was one of these we were exploring. For hundreds of years such caves have been used by the islanders as shelter, particularly in bad weather, and now they're becoming tourist attractions.
What makes a cave like Ulupaka particularly exciting to explore is the fact that it is undeveloped, the only light comes from the handheld lamps, the surface underfoot is the natural stone of the cave and the only changes to make things easier for tourists are a rope to assist in climbing down one particularly steep slope and a homemade wooden ladder to help reach the exit.
I've no idea how big it is, and Darren wasn't sure either, but it took us two to three hours to explore, the caverns were mostly spacious - though at a couple of places we had to squeeze through small gaps like "the keyhole" and "the squeeze" - and the exit emerged a few hundred metres through the jungle from the entrance hole.
As well as the xylophone, the cave is filled with a vast array of limestone formations - great clusters of stalactites and stalagmites, huge pillars where they have joined, giant stone curtains draped from the ceiling - as impressive as any I've seen in caves around the world.
Darren pointed out one that looked like the Eiffel Tower, another resembled a penguin, another was a bit like a lion. Yet another he highlighted with his torch and said, "I call that the chicken. It looks more like another bird I've seen on television but I don't know the name."
I commented that it looked to me like a turkey vulture and after I described what they look like he agreed enthusiastically. "That's it. That's the bird. It's a turkey vulture." So, if you visit the Ulupaka Cave one day, you may find my little contribution to Niuean tourism: the turkey vulture stalactite.
Getting there: Air New Zealand has a weekly service to Niue, which runs on Saturdays. Airfares start from $329 per person, one way from Auckland.
Where to stay: The 22-room Matavai Resort is at email@example.com.
What to do: You can book Tali's Cave Tours through the Niue Tourism Office in Alofi.
Further information: See niueisland.com.
Jim Eagles visited Niue with help from Air New Zealand and Niue Tourism.