Lucrecia was a scientist working for Shinra about 30 year's ago. She worked on the Jenova project with Professor Gast and Professor Hojo in the Nibelheim Mansion. Vincent, then working as a Turk, was also there. Vincent fell in love with Lucrecia and proposed, but she turned down his offer of marriage, saying that she loved Hojo instead. Soon after she became pregnant with Hojo's child. Hojo injected Lucrecia with Jenova's cells while the child was still in her womb. She became very sick, and died when the child was born, but the Jenova cells in her body meant that her soul would never completely die. Her child was named Sephiroth and was brought to Midgar by Hojo, where he grew up without ever knowing who his parents were.

In order to find Lucrecia in the game, you first need to acquire a submarine (found on disk 2) or a Gold Chocobo. Travel by an underwater tunnel towards the Nibel area and then leave the water. You will be in a sort of lagoon, surrounded by mountains. The cave is behind the waterfall. This can also be reached by chocobo by climbing over the mountains. By returning here in Disk 3 or 4 you can acquire the Limit Break Chaos and the weapon Death Penalty.