By the time he was diagnosed with terminal pancreatic cancer in 2007, Mischa Weisz had all he needed to face the fight of his life. A child of Holocaust survivors, he felt distant from his parents and had no idea of his own heritage until he was well into his teens - too late to adopt it as his own.

When Mischa and his first wife split, he battled for custody of their son and daughter, emerging as an unlikely but devoted single father living on unemployment insurance as he plotted his move into independent business. His work with computers and bank machines positioned him to take...