When American newspaperman and adventurer Henry M. Stanley comes back from the western Indian wars, his editor James Gordon Bennett sends him to Africa to find Dr. David Livingstone, the missing Scottish missionary. Stanley finds Livingstone ("Dr. Livingstone, I presume.") blissfully doling out medicine and religion to the happy natives. His story is at first disbelieved.

Socialite Judith Traherne lives a lavish but emotionally empty life. Riding horses is one of her few joys, and her stable master is secretly in love with her. Told she has a brain tumor by her doctor, Frederick Steele, Judith becomes distraught. After she decides to have surgery to remove the tumor, Judith realizes she is in love with Dr. Steele, but more troubling medical news may sabotage her new relationship, and her second chance at life.

In 1915 France, Major Brand commands the 39th Squadron of the Royal Flying Corps. The young airmen go up in bullet-riddled "crates" and the casualty rate is appalling, but Brand can't make the "brass hats" at headquarters see reason. Insubordinate air ace Captain Courtney is another thorn in Brand's side...but finds the smile wiped from his face when he rises to command the squadron himself. Everyone keeps a stiff upper lip.