While eating his dinner on a rainy evening at the Hayward Stables Guesthouse in Wales, Charlie notices a couple quietly arguing next to him. It has been a year since his last visit to the inn, and almost everything is the same: the rain, the furniture, the old barn. He continues picking at his food, unable to muster up an appetite, and listens to the couple’s hushed tones. The woman leaves eventually, and after admiring her form as she is walking away, Charlie makes casual conversation with the man, who he has spoken to once before. Charlie reassures the man there are plenty of sights around the area, and when asked what he plans to do here, Charlie responds he is geo-caching. He briefly explains his wife Lyndsey and he enjoyed the activity and that they had come here last year to conduct it. The conversation ends, and Charlie steps outside to smoke and reminisce, thinking of the geo-caching he and Lyndsey had done at the Church of Saint Brynach. Lyndsey had always insisted they follow the “rules” of geo-caching, purchasing the gaudy waterproof jackets and hiking boots each participant wears, as well as placing a new object in each cache for every object they took away. She and Charlie also had inside jokes they made up while trying to discover cache locations. Lyndsey had especially enjoyed the locations with clues, including the church.

Upon returning to his room, Charlie hears that the arguing couple has reconciled, based on the coital noise coming through the wall. To lull himself to sleep, he masturbates as they have sex. The next morning, he goes directly to the inn’s old barn, wondering if the owners have locked it since the incident with the Castellmarch man last year. Charlie brings with him a Tupperware box with little mementoes of his life with Lyndsey, hoping to leave them in the barn as remembrance for what happened. That day, he and Lyndsey had returned to the inn after enjoying a walk around the surrounding fields. Growing passionate with each other, they decided to have sex in the barn. When they finished, they found that an old man wearing a flapped hat had been watching them silently. Hoping to break the awkwardness as Lyndsey was getting dressed, Charlie asked the man if he was staying at the inn as well, but he gruffly responded he was from Castellmarch and was going to Carreg Castle. He played a song on a flute-like instrument for them, then taunted them while holding Lyndsey’s boots so they could not leave. He made an unnerving joke about a donkey, then called Lyndsey a “filly” who “likes a good ride.” Angry and eager to escape, Charlie and Lyndsey took the boots and reported the man to the owners of the inn. Now, Charlie places his Tupperware of memories on the hay where the couple saw the man.

Emerging from the barn, Charlie sees the couple from the night before. The man tells Charlie they are hoping to see some of the sights Charlie was speaking of at dinner, and Charlie suggests to him Carreg Castle, saying he is traveling there as well. As the couple is driving away, Charlie notices the woman sitting in the passenger seat looks strangely like Lyndsey. In his own car, he drapes Lyndsey’s waterproof jacket over the passenger seat, hoping it will bring him his wife’s company. He drives to Carreg Castle, the last location on his six-month journey of caching away his memories with Lyndsey. The year before, he and Lyndsey had been searching for the five geo-caches hidden at the castle, demystifying the clue in one cache to find the next. They suspected the last cache to be in the castle’s well, which has been said to have healing properties for eyes and ears. The couple descended deep into the castle, finding the well, but no cache. Suddenly, they heard footsteps, and a man’s voice angrily called out, asking who was spying on him. Charlie and Lyndsey instinctively knew it was the Castellmarch man, and once shining the light of Lyndsey’s phone on him, they saw, to their shock, the man had removed his hat to reveal horse’s ears. He ran at the couple on all fours, jumping on to Lyndsey and rocking his pelvis against her back. Charlie and Lyndsey scrambled to get him off, but the man chased her through the passageway of the castle, forcing her to fall with him off the cliff that the structure is positioned on. Charlie never found their bodies. On their final geo-caching trip, Lyndsey had been taken and he had been left behind.

During the struggle, Charlie had ripped the man’s pocket, causing the flute to fall out. He had taken it and the hat with him after the accident. In the chamber with the well, Charlie puts on the hat and takes out his last Tupperware container. He removes the flute from the box and plays the song the Castellmarch man had played in the barn, hoping it will bring Lyndsey or even the man back. He prays for anyone to come, and finally he hears the arguing couple from the inn. He hides against the chamber’s walls and waits.

The Castellmarch man was originally March Amheirchion, a knight of King Arthur who had horse’s ears. Whenever someone discovered this, March would kill them and bury them in a bed of reeds. Eventually, a boy made a flute out of these reeds and, when he played it, heard the flute reveal March’s secret. It is speculated March’s children continued his line to the present.