The Queen Mary was a Cunard ocean liner.
The Fourth Doctor landed on the vessel in October 1963, during a voyage from Southampton to New York City. He discovered that physicist Peter Osbourne had built a time visualiser prototype and was testing it in Cabin 672. It was sending ripples backwards and forwards in time, capturing the fragmentary essences of people in the moments of their worst despair. The Doctor destroyed the machine, but the gestalt of spirits remained bound to the ship, with Osbourne included in their number. (PROSE: Ghost Ship)