The Pipes of Orpheus

As others around them perish, the children - prisoners of the Pied Piper - study the piper's every move hoping to find his weakness. In a book in his library, they discover his true identity - none other than Orpheus, eternally pining for his lost Eurydice. Realizing they have no other choice, the children venture into the Underworld to rescue the piper's lost love.