In "The Lady of Shalott", why does she go to her window? What happens when she does?
The "fairy Lady of Shallot" weaves a magic web by night and day, content to see the world through the reflections of a "glass" or mirror. Eventually, she becomes tired of such a refracted existence murmuring, "I am half sick of shadows," she says.
She left the web, she left the loom,
She made three paces through the room,
She saw the water-lily bloom,
She saw the helmet and the plume,
She looked down to Camelot.
Out flew the web and floated wide;
The mirror cracked from side to side;
"The curse is come upon me," cried
The Lady of Shalott.
The Lady of Shallot's curse was that she could not leave the web, she could not leave the loom, and to do so would be to bring the magical curse down upon her. With the mirror cracking from side to side the curse comes into effect. We don't know exactly what the curse was, we just know that it results in her death. The Lady of Shallot flees to the riverside, secures a boat with "The Lady of Shallot" as its name, sings her last song, and is cast adrift. At the discovery of her dead body in the boat, Sir Lancelot muses at her beauty and her grace.