I found the journal of a Church pastor from the 1200s. The Pied Piper is real.

The Legend of the Pied Piper

The logs end here. I checked up on my facts again before committing the story to be transcribed- and found a lot that seemed to match up.

The tale of the Pied Piper of Hamelin came about in 1284 AD. It told of the Piper leading away rats - an evident, inescapable reference to the Great Plague. But what has always been considered odd in the European folklore community, is that the Black Death didn't start till almost fifty years later - in 1328. Yet the story originated when it did; infact there was even a stained glass window in the erstwhile town church of Hamelin, depicting the events of the story. None of which would have been possible if the Plague had not even started yet.

However, after reading the Father's journal, I believe I may have an answer. You see, the story of the Piper ends with a very specific little detail. It says that there were two children who were saved, because they could not follow him like the other children did. One was a little girl who was deaf and could not hear the music, the other was a boy with deformed legs who could not keep up with the group.

The Piper never did get all the children like he had wanted to. And maybe, because of that, what should have happened instead only became a temporary reprieve. Instead of removing the Black Death from the annals of history, all they could do was postpone it by half a century. Whatever the Herald was, his loyalty lay with something else. And Its wrath is what the world felt when the Plague killed a third of all who were alive then.

To this day, there is a street in Hamelin associated with the Pied Piper. It is said to be where the children were last seen, rushing happily into the west, enchanted by an otherworldly melody. That street is, and always has been called - Bungelosenstrasse.