Helestican

The Helestican were an alien species which had time travel technology. They also built their space ship with time travel technology. In 2015 a Helestican ship was inside the basement of Ross McNamara's school. Ross went into the spaceship. The chronal vapours of the spaceship sent echoes of Ross through time and briefly transporting him to the year 2115. The Twelfth Doctor suggested Ross's echos might be the legendary ghost reported at the school. After exploding Ross's school, the Doctor returned Ross to his home in 2015. (PROSE: Haunted)