It happened when the whole truth about the titans was unraveled. The Survey Corps had won against the ones who had hidden everything for 100 years, and mostly, against the fake royal family. As such, Historia was now capable of rising to the throne, being the only heir. Things were about to change for humankind.
But, before any major moves, investigations inside Wall Sina were necessary, and it was in one of those that they found her.
Together, Levi, Hanji, Jean, Sasha, Connie and Armin went to investigate an underground facility right next to the royal palace where experiences were performed on animals. At least that's what the people in charge said. In reality, there had been a great number of missing people, poor people, and the most probable place for them to be was in that facility.
But as they went further inside the creepy place they could only find remains, both human and animals'. Until Armin came across with a suspicious looking door that said "Restricted Area – only higher staff allowed". He tried to open it, but it just wouldn't budge. So he called for the rest of the crew and Levi, with a really strong kick, blasted the doorknob, and with an awful sound, the door opened.
Careful, as to avoid any traps, they went inside the dark room, only to find it empty. Or so it seemed at first. After adjusting their eyes to the darkness, they quickly found someone lying down on a metal table. Apparently, it was a woman, and both her arms and legs were tied with ropes to the table. Her eyes were covered with tape, so the only visible parts of her face were her nose and lips. Both her breasts and lady parts were also surrounded with tape, so, the rest of her body was exposed to the cold hair of the room.
Next to the table was a set of flasks, each one with a more difficult name than the one before. Hanji also spotted some documents and after viewing them quickly, she easily understood that they were testing medicines on the lady. But to test the medicines, the unconscious lady needed to have contracted the diseases, and as such, according to the papers, the ones responsible for those experiments injected her with viruses, one at a time and later, introduced the corresponding medicines.
As Hanji transmitted her conclusions to her teammates, the more horrible humankind seemed:
"But I have to say, I'm surprised. No normal human could withstand such experiments, one after the other. Just who is this woman?!"
Immediately after Hanji said this, the woman woke up.
"Please… I beg of you, stop this. It's already clear that these medicines work, and it's also clear that I won't give you any information on the Survey Corps. So, before I die, I want to at least feel the air on the surface…" – she said while tears ran through her face – "I want to see him again."
Everyone stared at each other quietly, until Armin broke the silence.
"Ah… you're mistaken… hum… we are here to investigate this facility and to save any one that was made prisoner. We are from the Survey Corps, you're ok now!"
"What?!" – the woman instantly reacted – "Oh god…" – more tears started running – "I must be dreaming…" – she then gasped – "Oh yeah… hum… I really want to know something first. Is my cousin alright? And my friends! Are they ok too?" – she asked with a worried tone.
While the crew released her legs and arms, Connie asked "You know, it would help if we actually knew who you are talking about."
"Oh yeah… silly me, I didn't even tell you their names. Well, my cousin is the one called Smith. Erwin Smith. Know him? It's the blond guy."
That's when everyone in that room suddenly stopped what they were doing and with a stupefied face turned to see the surprised Captain who usually carries an annoyed face. Then, Levi only said one word, and that was more than enough for the woman to quickly unfold her eyes and petrify for a brief moment: "Rose?"