num_pages: 92
description: The Doctor is worried by the statistically significant number of recent alien visitations to Earth and a chance comment from Ace leads him to the answer; the TARDIS is still infested with energy from the Mandragora Helix which has been hiding away and growing in strength for years and is now strong enough to draw the Doctor and other alien species to Earth for some reason. As he and Ace search the TARDIS they find its corridors warping out of shape around them and find themselves in the cellar of the Falling Star nightclub in turn-of-the-century London. Captain Muriel Frost and Sergeant Jasper Bean of UNIT have infiltrated the club to look for evidence that its owner Stranks is dealing the drug Mandrake. When Stranks finds them Bean shoots a bouncer through the chest as he and Frost escape but Stranks transforms the dying man into a monster which pursues them and kills Bean. Frost meets the Doctor and Ace and together they escape when the Doctor tricks the energy-based monster into shorting itself out on a metal staircase.Back at UNIT HQ Frost informs the Doctor that alien energy patterns have been detected in samples of Mandrake and the Doctor suspects that there may be a connection to his own problem as Mandrake is another word for Mandragora. He Ace and Frost take a backup team to the nightclub where they find the cellars full of Mandrake processing facilities and a massive energy rig in the shape of a double helix. The cellar is now linked directly to the interior of the TARDIS and the Doctor realises that the Helix is using his ship as a bridge between Earth and the Vortex; however the strain is too much for the TARDIS which could blow up at any moment.Stranks captures them all and reveals that Mandrake is designed to sap its users' willpower turning them into willing slaves of the Helix. The Helix has been testing the Doctor for some time setting him against alien enemies on Earth to see how he deals with them and it is now confident that it can out-think all of his plans. Stranks summons the Helix to Earth and the youths on the dance floor all Mandrake users welcome the energy into their bodies transforming into energy-monsters. As the Helix's power grows it will consume the Earth and transform it into another energy helix -- and the two combined will form a double helix of pure energy capable of reproducing itself and consuming the Universe. As the critical moment approaches the Doctor finds himself powerless and hopeless -- until a sudden power surge detonates the power rig banishing the Helix from Earth once again. The Doctor concludes that the TARDIS finally succumbed to the strain and exploded but when he and Ace return to UNIT HQ with Frost the TARDIS is waiting for them. The Doctor realises that it just jolted into gear at last and materialised breaking the link with Mandragora and saving the world. 
language: English
title: Doctor Who: The Mark of Mandragora
publisher: Virgin Publishing