A crystal that promised to conduct electricity without loss at room temperature turned out to be like a house of cards: touch it and it falls apart. Two compounds (one with silver, one with gold) were considered superconductor candidates, but tests showed that neither can withstand even ordinary conditions.
In the silver variant, the lattice simply collapses. The gold one holds up better: the lithium-gold framework remains intact, but the hydrogen atoms inside clump into pairs and start wandering freely through the crystal, like passengers without tickets in an empty train car. It is this disorder that doesn't completely kill superconductivity but weakens it: calculations give a transition at 22 K — colder than a freezer and far from room temperature.
These materials were previously predicted to be superconductors at ambient pressure and room temperature. Now it's clear that the hydrogen doesn't stay put but wanders, and that changes the whole picture. But the gold-lithium framework itself held up, so one can try to stabilize the hydrogen by choosing other metals or slightly tweaking the composition.
This approach is like fixing a leaking roof: the house hasn't collapsed, but you need to stop the leak to make it dry and warm inside. If the hydrogen can be held in place, room-temperature superconductivity moves one step closer.
A superconductor at 22 K can already be cooled with liquid hydrogen, which boils at 20 K — simpler than the helium systems used for classical superconductors.
In Arthur C. Clarke's novel 'Childhood's End', aliens use superconductors for levitation — a dream that drives the search for materials like Li2AuH6.