When the triplicator malfunctioned and made two copies of Red Dwarf, the Dwarfers had to visit the "Low" version in order to find half of the triplicator, so that they could reverse the process.
Their first encounter with the Low crew was when the High Kryten was shot several times and then he and the High Cat were blown up by a grenade. Lister ran off into the cargo bays and encountered the Lows one at a time.
He first came face to face with his own Low counterpart, who was a bearded, one-eyed, leather clad cowboy who showed no qualms about indiscriminate killing. The Lows described him as the part of Lister that tortured insects, burned his best friend's neck with a magnifying glass, who loved horror movies, wanted his friends to fail and lusted after meaningless sex. He had an annoying high-pitched laugh and delighted in torturing his original counterpart.
The Low Cat was a savage, sabre-toothed animal who wore animal skins and happily ate the raw remains of his "High" self. He spoke with an exaggerated southern american accent and seemed to enjoy pain, burning himself with a coffee pot and smiling when Low Kryten headbutted him.
Low Kryten was covered in oil and had a physical and verbal stammer, indicating that he was worn out and malfunctioning. He spoke with a rasping, lower pitched voice than the original Kryten.
The Low Rimmer was perhaps the most disturbing of them all. He was a depraved and perverted transvestite, who wore a variety of bondage gear and stockings. He wielded a holowhip and lashed Lister with it, threatening to "have" him. He had black hair and wore his H diagonally on his forehead.
The Low Holly had a short, black bob haircut and wore black make-up. She seemed to enjoy violence and sadism as much as her crewmates. Her screen seemed to be of poor quality and crackled with static.
The Lows tortured Lister, placing an implant into his spine that allowed them to control his actions. They forced him to shut his nose in a cupboard, burn his groin with hot coffee and eat a tarantula. They then gave him a knife and sent him to kill his crewmates. They explained that they wanted Starbug so that they could escape their decaying vessel. They made Lister stab the High Lister and crush High Rimmer's lightbee. Kryten managed to chloroform Lister before he could kill anyone else.
When the Dwarfers managed to escape the Low Red Dwarf and restore the original, they thought that they had seen the last of the Lows, but it was obvious that someone was still controlling Lister's body. The Cat heard a high-pitched laugh coming from one of Starbug's closets and fired his bazookoid through the door. The Low Lister fell dead from the cupboard (RD: Demons & Angels).