The Nibelheim Cloud entered was not the Nibelheim he and Tifa remembered from five years ago. The town seemed like nothing bad ever happened to it. In fact, it seemed so fine, Cloud began doubting his memories. Upon investigation, though, it became obvious something is wrong. Most citizens would get overly defensive on any mention of Sephiroth or the towns destruction.
Even more disturbing, some of the people there, namely those dressed in black acted unstable, constantly talking about joining Sephiroth and some sort of Reunion. Through one of them, Cloud found out Sephiroth is at the Shinra mansion. The ground floor of the mansion held a book written by some Shinra researcher. He mentioned a subject that has been put in suspended animation in the cellar. The key to his room was stored in a safe and the pieces of the combination were hidden in the mansion. He also left several clues about where the pieces might be:
One of the pieces was supposed to be “in the place with the most oxygen”. There was a room filled with plants in the upper left wing, and this is where Cloud managed to find the first part of the combination. Another piece was “behind the ivory’s short of tea and ray”. This one was difficult, but Cloud managed to remember that piano keys used to be made from ivory. Once he remembered that, it became clear that “tea and ray” were actually do notes “Ti” and “Re”. The second part of the combination was found next to the piano, again in the upper right wing of the mansion. The third piece was found by simply following the instructions in the message. There was a chair in the upper left wing, placed next to a squeaky floor. From that point, one simply needed to follow the required number of steps in the right direction in order to find the third part of the combination. The fourth and final piece was found in the research notes themselves. It was written in invisible ink, right underneath the third clue.
The final combination to open the safe, thus, was “right 36, left 10, right 59, right 97”. With this, the safe was opened and the group was attacked. The monster was tough, but the party managed to dispose of it. As a reward, they gained the cellar key, something called Cosmo Memory, and a materia which can be used to summon Odin.