Extraction chamber 7 was the Time Lord extraction chamber that the Twelfth Doctor and the Time Lords used to pull Clara Oswald out of the last moment of her time stream to question her about the Hybrid.
After the Eleventh General explained to Clara the mechanics of the chamber and why they had extracted her, the Twelfth Doctor stole the General's staser and shot him, claiming a human-compatible neural block in the process. The regenerated Twelfth General tracked the Doctor and Clara to the Cloisters from the extraction chamber before leading a force there. (TV: Hell Bent)
