The Shadow The Shadow was a cowled humanoid who served the Black Guardian on a mission to acquire the Key to Time . Biography . The Black Guardian gave the Shadow the task of getting him the Key to Time , just as the Fourth Doctor had been sent by the White Guardian . Rather than trying to find and collect all six of the disguised segments , he located the sixth segment , and waited for over a thousand years for the Doctor to arrive with the other five . The sixth segment was encoded in the genetic structure of the sixth royal house of Atrios , passed down through six dynasties to the sixth child , Astra of Atrios . The Shadow set Atrios to war against its neighbouring planet Zeos , taking control of the Marshal of Atrios and setting a third planet between them to prevent them from seeing the other . He hired the renegade Time Lord Drax to construct the computer Mentalis , which would control Zeos to continue to fight even when its population was completely destroyed . He monitored the Fourth Doctor and Romana I ' s quest for the first five segments of the Key to Time , and waited for them to arrive to find the sixth . When they did , five years after the war had begun , he took the Doctor ' s TARDIS , trying to break into it with no success , and ordered the Marshal , who had captured the Doctor and Romana , to treat them well and not allow them to die yet . He ordered his Mutes to capture Princess Astra , forcing her broadcast to Atrios that she had been captured by the Zeons . He then captured the Doctor when he tried to get to Zeos , and tried to use a control device on him to give him the other segments ; when that did not work , he tortured him until the Doctor agreed to bring them to him from inside the TARDIS . The Doctor then claimed it was impossible to bring them out without the sixth piece , at which the Shadow disappeared to wait for the Doctor to make a mistake . He tried to make Princess Astra tell him the secret of the sixth segment , using her lover Merak as leverage , without succeeding . After this , he fitted a control device on her to help him capture Merak , and then lure the Doctor and Romana to the third planet . He made her rescue the wounded Merak , and use him to get past K9 Mark II , who was guarding the TARDIS , but found it was still locked . He lured K9 away using a false distress call , and fitted another control device on it , putting it under his control . He then made Astra and Merak meet the Doctor and Romana , to try to go with him into the TARDIS , but the Doctor suggested she went back to Atrios to tell her people she was free ; after they split up , he made her leave Merak , revealing that she was under his control . He made her flee back to the Doctor , claiming she was being chased by Mutes , at last letting her gain entry to the TARDIS ; however , the Doctor was aware that she was under his control , and the Shadow told her to go with them , to bring him Romana . He made Astria lead Romana into another trap where she was captured too , and tortured to tell him everything she knew . He used a distress signal to lure to Doctor away , sending K9 to capture him , along with holograms of Romana and the Doctor , and took him to a cell . The Shadow then ordered Drax to get into the Doctor ' s cell to try to convince the Doctor that he was trying to escape from the Shadow , so they could go to the TARDIS to escape , and he could steal the Key . Instead the Doctor saw through Drax , and convinced him to work with him . The Shadow ordered K9 to bring the Doctor to him , but the Doctor pushed K9 down a slope to Drax , who removed the control device , freeing him from the Shadow , only for a Mute to capture the Doctor . This time , the Shadow tortured Romana to convince the Doctor to bring him the first five pieces , who reluctantly agreed . As he went , the Shadow removed the control device from Astra who was nearly ready to be transformed into the final segment . Drax shrunk the Doctor , who had just opened the door to his TARDIS , and himself ; the Shadow saw this , and tried to go into the TARDIS , but was blinded by its lights , and ordered a Mute to get the Key . He took it to Astra , who transformed into the segment , but the Doctor managed to get to it first , hiding on K9 before being restored to full size by Drax , and escaping to his TARDIS . The Doctor saw to it that a nuclear missile , fired by the Marshal ' s Command Capsule , struck and destroyed the Third Planet , killing the Shadow , though as he died , the Shadow reported his failure to the Black Guardian . ( TV : " The Armageddon Factor " ) Nature and powers . Like the Black Guardian , the Shadow revelled in chaos and destruction , describing the destruction that would be caused by the Black Guardian ' s ultimate goal of setting the two halves of universe to destroy one another as " music in [ his and the Guardian ' s ] ears " . He employed the renegade Time Lord Drax to work for him , and communicated with the Marshal on Atrios by a secret video communications link and manipulated him , using a control device to ensure he acted exactly as required , which he later used on Princess Astra and K9 . He was able simply to disappear from Zeos to the Third Planet , along with the silent Mutes under his command , who lived in the third planet . The Shadow had an instinctive aversion to bright light , which the defence systems of the Doctor ' s TARDIS generated to repel him . He claimed to have waited such a long time for the Doctor that " even another thousand years would be nothing for me . " He saw himself as the Fourth Doctor ' s adversary , who he believed to be inferior to him for falling into his trap , but the Black Guardian had planned that the Shadow would fail , calling him a " whimpering wraith " . ( TV : " The Armageddon Factor " )