How Rubik’s Cube craze spawned rival’s Hong Kong puzzle career, and why, at 78, he’s out to finally crack the China toy market

Uwe Meffert made his first twisting puzzles for a research project. They stayed in a drawer until the Rubik’s Cube became a hit and he took them to Hong Kong toymakers; 35 years and 230 million cubes later, he’s turned to China