No one is certain of exactly what it is or why it’s happening, but Esther and Arthur Herzfeld can be sure of one thing: Something very serious is happening to their four children. Tziporah, Rivka, Tzvi, and Racheli Herzfeld are battling with a “mystery illness,” that is slowly robbing them all of their ability to walk. Though they started out as healthy and active children, the Herzfeld kids began to struggle with their walking one by one.

Stumbling, then falling, then being unable to get up from falls, each child's condition progressed to a different point of severity. Eighteen-year-old Tzvi can no longer walk at all, and his sisters are forced to walk slowly and carefully, with the terrifying knowledge that they could fall at any moment, unable to get up on their own. “Imagine being completely healthy one day, and then one day you go to sleep, you wake up, you start walking funny and…