To modern eyes, the little wagon in a Berlin museum looks like a model of an old horse-drawn cart. Solidly made, about as big as a baby's cot, it is in fact a handcart, to be pulled by people, not animals.
It's not in a museum because it's anything special, but because of the story it tells. It's one of millions of similar carts that German refugees dragged behind them as they trudged west in the dying days of World War II.
Between 1945 and 1950, 12 to 14 million German-speaking people fled or were forced from their homes in central and eastern Europe to live within Germany's post-war borders. About two million are believed to have died along the way.
If you know what you're looking at, the battered wagon tells many stories - about the settling of old scores, the redrawing of borders, and Germans' double role as victims and perpetrators of war.
You could call this the Neil MacGregor method of teaching history: show an object, tell its story, and in the process reveal the world in which that object was made. He did the same thing in his 2010 book A History Of The World In 100 Objects. Like that, this book is tied in with a BBC radio series and an exhibition at the British Museum, of which MacGregor is director.