An unorthodox marriage between capitalism and charity, 'The Invisible Heart' tracks a social innovation that promises to solve society's most intractable problems. Social impact bonds are making strange bedfellows — social workers and Wall Street bankers, the homeless and venture capitalists, conservative and liberal politicians. From the halls of power to society's struggling underclass, this film follows an unusual cast of characters as they confront the ethical questions at the heart of an in...