Who holds the hK?

by Ron, on the 17.15 from King's Cross

In a hand of bridge:

Each player has 10 points.

No-one has a pair of Aces.

South holds the cQJ.

The dQ and the dJ are in different hands.

East and West are void in the same two suits.

North has a red Ace and no Jacks.

Who holds the hK? This problem was given to one of the editors on a train; the original source is unknown. The answer may be found here.