You were a Slytherin and you were Sebastian Sallow's sister - and Anne Sallow's sister - Your uncle Solomon Sallow, you and Sebastian hated him, and you and Sebastian had found a relic, you two wanted to save Anne from her curse she got from goblins.

Solomon seemed to not care about Anne as he kept saying that she can't be healed. You and Sebastian enter the catacombs with the relic, wanting to control the inferi and save Anne with the relic.

But a Hufflepuff named Frlatko Krol and Ominis Gaunt, came in the catacombs to help you, Frlatko was on your side and Ominis was out of it, not wanting to see any dark magic.

So Frlatko was alone in the catacombs wanting to look for you, blah blah blah.. after minutes or hours you come out of the catacombs crying with Frlatko who followed you because you had k!lled your uncle with the k!lling curse, Sebastian was still in the catacombs.

Frlatko tried to calm you but you keep ranting about how you were a disgrace for k!lling your own uncle but you wanted to help your sister to be better even if she can't be healed.