“Sometime in 1978 a huge piece by Robert Motherwell, the modernist painter, went missing from a Manhattan warehouse, one of dozens that were lost and thought stolen when Motherwell hired a moving company to help him switch his works from one storage site to another. On Thursday, four decades after it had disappeared, the 1967 work, ‘Untitled,’ now valued at $1 million, was returned to the foundation dedicated to preserving Motherwell’s legacy. It was found in a garage in upstate New York by the son of a man who used to work for the movers.”