Coal Hill defenders
From Tardis Wiki, the free Doctor Who reference
The Doctor's team refers to a group of four students and a teacher from Coal Hill Academy that were assembled by the Twelfth Doctor, to protect the school from any alien threats that came through a tear in space-time. The tear had been opened by an excess in artron energy around the school, and after an attack from Corakinus and the Shadow Kin the Doctor was able to close the tear. However he warned that he couldn't fully close the tear, and that Coal Hill would continue to transmit like a beacon across the universe to any nearby aliens who wished to use the tear to enter to Earth.
