Citadel: Rita's Sister

Citadel: Rita's Sister is obtained by speaking to Rita at Flux in the Wards.

She wants you to speak to her sister in Chora's Den. Afterwards, Chellick will catch you at the door, asking to see you at the C-Sec Academy. Once you've spoken to him and agreed to help, this becomes Citadel: Rita's Sister and Chellick.