The reset is a key moment that occurs during Layer 13. Because of all the damage she has caused to the real world and especially to her friend Alice, Lain chooses to start the world over while erasing her own existence.
As a consequence, all the characters who were playing a role linked to Lain returned to their normal lives. The Men in Black became construction workers and Eiri remained a dissatisfied employee of Tachibana Labs. Alice grew into an ordinary and well-adjusted young lady.
After the reset, Lain appears before an older Alice. She still appears to be the same age.