A family on the verge of death because of their cat, an infected ear lobe turning into a crippling illness, physical pain that leads to attempted suicide: in Maux Mystères, people who are told they have a rare disease, often obscure even for doctors, see their lives confined to a relentless and ultimate quest for the right diagnosis. And while doctors are trying to find the cause, these mysterious diseases keep progressing and inevitably cause damages that are often irreversible. This window on the life of these people offers a human perspective on the urgency of getting an accurate diagnosis when standing between life and death.