Alice first appears within the preliminaries as the "wandering girl," a rumored female ghost that will suck out a victim's soul if they respond to her. Sensing a strange presence staring from behind, she appears before the Initial Protagonist without any footsteps or sound of breathing once he looks back. She quickly fades away without saying anything. Meeting her again, she asks if he isn't afraid of her, and introduces herself as Alice. She has a faint smile on her face afterward, and invites them to have tea sometime.

Throughout the week, they convince Hakuno to "play games" with them, noting two people named Yamada and Suzuki as previous "playmates." On the first floor of the arena, Alice and Alice summon a monster that is initially believed to be a Berserker class Servant. After the "Servant" is defeated by a newly created Vorpal Blade only Alice and Alice remain. It is then deduced that the monster was not the children's Servant at all. On the second floor of the arena, the two girls change the area around them in to a place where all intruders forget who they are over time, eventually dying. When Hakuno survives this encounter the first time, it is revealed a powerful Reality Marble has been put in place. The hero is able to diffuse the area of effect by saying their name out loud. It is this, and helpful advice from Touko Aozaki, that imply Alice's servant is of the Caster class and is actually the second Alice.

It is revealed soon after that Alice's Servant is Nursery Rhyme, the embodiment of the world of picture books for children. Because Nursery Rhyme does not have its own body, it manifests itself as the will of its current Master; in this case a mirror version of Alice herself, who wished for a friend to ease her loneliness.

In Alice's final moments, she confirms what had been insinuated the entire time: Alice is already dead in the real world. However, her spirit is able to live on in the Moon Cell as a "cyber ghost." As she and Caster lay dying, Alice held her Servant's hand and told her it's would be okay. With a final smile, she disappeared.
(Source: Type-Moon Wikia)