Ever since he can remember, even as a boy growing up on a small farm in Michigan, Ken Martin has battled betrayal by his own body. Now 50 years old, Martin was born with hemophilia, and he bleeds almost uncontrollably from a cut. If an internal vein or artery is injured, the blood it carries pools in an intensely painful balloon under Martin’s skin. When that happens in his knees, as it frequently does, he must hobble on crutches or stay in a wheelchair until the bleeding slowly stops.