The Lost is the spirit of a child named Isaac that died by suffocating in a toy chest and became "the lost"
The lost wonders around in his purgatory basement where he fights monsters with his tears that attack him and go deeper through more trapdoors
The lost is crying, scared and confused
The lost (Isaac) doesn't know he is dead he thinks his mom is trying to find him to sacrifice him to god to prove she loves him and how he thinks how he got in this place was through a trapdoor under his rug