For over 50 years, a Canadian nurse named Rene Caisse treated thousands of cancer patients with her own secret herbal tea named Essiac - Caisse spelled backwards. She originally obtained the natural formula from native Ojibway Indians and brewed the remedy herself in her kitchen. Caisse was a devoted healer and tireless champion of using her nontoxic treatment for cancer as an alternative to destructive radiation and chemotherapy.

Caisse fought for decades to have Essiac recognized and accepted by the broader medical community, but - constantly challenged by large powerful pharmaceutical companies with political influence - the treatment continued to remain controversial and illegal. Believing that promoting and using her cure to be her true calling, she continued to treat patients for free despite threats of imprisonment. Her patients, many of whom believe that Essiac helped drive their cancer into remission or cured them entirely, spoke passionately about her and came to think of her as an angel.

In Calling of an Angel, Dr. Gary L. Glum tells Caisse's inspiring story and presents the argument for allowing this long-suppressed treatment as an option for patients and families currently battling cancer.