"We've been invited to witness a bonfire of marijuana by the Taliban. Anyone interested?"

"We've been invited to witness a bonfire of marijuana by the Taliban. Anyone interested?"

Amid the missionaries, mercenaries and misfits drawn to the world's most dangerous and volatile hotspots stands Dr John Parker.

From Cholera to Ebola is a captivating collection of true stories 25 years in the making.

Whether challenging the bureaucracy of refugee camps to cradling children as they died, Dr Parker operated far from his comfort zone, from the norms of medical practice and from the decencies of humanity.

His is a life that swung from heartbreaking hopelessness to sheer ecstasy as he battled PTSD to chase his next 'fix' over increasingly dangerous missions.

"There are some things you cannot be taught; you have to live them."