Mystery beneath

The couple later opened a tai chi school in the United Kingdom that attracted thousands. But they found themselves in a bottleneck.

"It was not enough for us to improve ourselves when we just learned from tai chi masters for two or four weeks a year," she says.

So the couple moved to Shanghai in 2000. They taught English in universities and happily learned tai chi under various gurus. After years of practice, Oliver found her occasional backaches had disappeared.

But her greatest pain came when her husband died in 2003.

She thought of giving up.

But she carried on to honor her husband.

"It was his real dream to come to learn in China," she says.

"He motivated me to come. Give it up and return and not pursue what we came here for? That sounded easy. But it wasn't easy at all."

She says her tai chi "family" - the masters and students - also provided a great support network.

Oliver's spiritual mentor then was master Dong Bin, who died in 2009 at age 88.

She says of their first meeting: "I had been told that his skill was of a very high level and for some reason I had a mental image of a powerful, big man. But my shixiong (fellow male student) pointed to a small, wizened old gentleman, sitting on the ground.