Ghost Ship

Perhaps sensing the Fourth Doctor's deepening mood of introspective melancholy, the TARDIS lands in the most haunted place on Earth, the luxury ocean liner the Queen Mary on its way from Southampton to New York in the year 1963. But why do ghosts from the past, the present, and perhaps even the future, seek out the Doctor? What appalling secret is hidden in Cabin 672? And will the Doctor be able to preserve his sanity as he struggles to save the lives of the passengers against mighty forces which even he does not fully understand?