(a) Vermin (rats) were infested in the town of Hamelin.
(b) All the rats came out of hiding and followed the Pied Piper, the piper lead the vermin to the river where they drowned.
(c) The Pied Piper was angry because the ungrateful townspeople and the mayor did not pay him back.
(d) When the Pied Piper played once more, the children of Hamelin came running out and followed the Piper into a portal that appeared in the Mountains.