Laura Popham was a caving enthusiast. She introduced the sport to her sister, Alena Sanderson, after she lost her house and job, thinking it would cheer her up, usually going on one trip a year together.
In June 2014 they organised a trip to Lost Johns' Cave (part of the Three Counties System of caves) to go in through Death's Head Hole, then through Gavel Pot with their first cave dive between Lost Johns' Cave and Gavel Pot. They informed the CNCC [Council of Northern Caving Clubs] and Laura's husband, Alistair Popham.
When they arrived they found conditions perfect for caving but saw no-one else in the cave and started their descent at noon. They followed the map, Laura noting that some of the places were smaller than she'd expected and one particular squeeze was far tighter. Shortly after the two stopped for lunch.
Alena had done some research into the cave, saying most people put the apostrophe in the wrong place: the story goes that two men named John came down into the cave but got lost and their candles went out, so it should be Lost Johns' Cave. Alena joked that she wouldn't mind getting lost underground with Laura, although her sister preferred to think of being underground as an intensely private affair.
They continued and began the cave dive. Alena tricked Laura into thinking she was hitting her head on the ceiling when underwater, causing Laura to get somewhat mad and have to take some time to let her panic subside. When Laura suggested they should go back, Alena agreed. As Laura turned away, she heard someone ask in a low grating voice how lost she was. Laura's snapped and terse reply that they weren't put a confused look on Alena's face as she looked back. At this point Laura was feeling very unsettled and eager to get above ground.
After diving back and encountering problems with tunnel distance and seemingly appearing in an unknown space, Laura waited for Alena to surface. When she didn't, Laura decided to move off, hoping to find somewhere she could turn around and head back as the tunnel was too narrow to do so there, along with the general confusion of not knowing where she was. Pressing on, the tunnel got tighter and narrower but when she tried to go back she found that the cave wall was directly behind her, trapping her. She screamed and her light went out.
Whilst in that confined space, she saw a far off light, like a candle flame, drawing closer. Upon seeing a pale hand holding the candle she thought she heard Alena screaming from far away and closed her eyes, wishing it all away. Opening them, she then realised the light was daylight and in less than an hour she was back on the surface. She screamed until Alistair and the cave rescue team found her. She had been underground for 24 hours, and after another 24, Alena was still missing. She was never found.
Jonathan Sims states that so many of the details here are "provably false": no permits were given to the sisters from CNCC but many others were for Lost Johns' Cave. Sasha stated that the path that Laura described was not possible. It is true that on the 15th June Alistair contacted the CNCC about the missing sisters, which Tim confirmed.
Laura was not found above ground, but a few yards from the bottom of Death's Head Hole, found kneeling next to a small pile of burnt out candles, which Alistair didn't recall her packing.
Laura had taken a video camera, which she didn't mention in her statement and Tim managed to get a copy of the video, the early parts of which match up with Laura's account of the descent. The last recording was from 2am on 15th June - no video, just audio. All that could be heard was whispering "take her not me" over and over again, and the sounds of water & scraping rock. This audio played in this manner for 2 hours and 43 minutes.
NOTE: There was some confusion about the name of the episode--whether it was "St. John's Cave," Lost John's Cave" or "Lost Johns' Cave." It is, as per Jonny on the forums, "Lost Johns' Cave" to indicate multiple "Johns."