Black and White ( audio story ) Black and White is the second story in the 2012 Seventh Doctor audio trilogy . Publisher ' s summary . The TARDIS arrives in the land of the Danes , where a young warrior seeks to rid the kingdom of Hrothgar from a cruel and terrifying demon . The brave young warrior is Beowulf ; the monster is Grendel . . . or so his name will one day be written . But what ' s written down in black and white is sometimes very far from the truth — as the Doctor knows , and his companions are about to discover . Plot . Part one . Lysandra Aristedes claims that she is no longer working for the Forge and that she and Sally Morgan are travelling with the Doctor . Hex believes that Lysandra and Sally are from the Doctor ' s personal future . However , Ace does not agree with this assessment as " The Tale of Beowulf " is still on the console room ' s armchair , as it was the last time that she saw him . According to Lysandra , the Doctor spends several hours a week training her how to operate the black TARDIS . Lysandra tells Ace that she , the Doctor and Sally have been on several missions in which they have defeated members of the Elder Gods . As Sally is attempting to comfort Hex , who believes that the Doctor is manipulating them all once again , the white TARDIS materialises around the black TARDIS . On the black TARDIS ' scanner , Ace sees her jacket on the hatstand , confirming that it is the white TARDIS . Upon entering it , Hex finds his boots in the console room . While Ace and Lysandra use the black TARDIS ' fast return switch to return to the Doctor ' s previous location , Hex and Sally remain in the white TARDIS . However , the white TARDIS immediately encounters turbulence in the Time Vortex . Its Cloister Bell sounds and it begins to dematerialise . Part two . The white TARDIS is caught in the black TARDIS ' slipstream and is dragged through the Vortex . This results in the white TARDIS losing all power . While Ace and Hex were sleeping , the Doctor began to grow the black TARDIS in the cloisters of the white TARDIS , which it refers to as its mother . Shortly before the materialisation of the black TARDIS in Denmark in the 5th century , the warrior Beowulf arrived in the kingdom of Hrothgar , where he hopes to defeat the monster Grendel . He is introduced to Hrothgar ' s court by Weohstan . At Lysandra ' s suggestion , she and Ace hide the black TARDIS using nearby bear skins . Having detected an anachronistic alloy , Lysandra believes that an alien vessel may have crashed in the area . Shortly after Hex and Sally leave the white TARDIS to investigate , it gradually becomes transparent . They soon discover that the white TARDIS likewise materialised in Hrothgar ' s court . Beowulf tells Weohstan that he is suspicious of Unferth , who has King Hrothgar ' s ear and appears to be wary of him . After dropping his mutton on the ground , Beowulf discovers that Ace is hiding under the banquet table . He initially mistakes for a boy . When she tells him that she is a girl , he refers to her as a " wench " and makes advances towards her . She responds by throwing a large chicken at him . In a swamp outside the castle , Lysandra discovers not only an advanced robot but an alien named Garundel , who proceeds to point his gun at her . He tells her that the robot is a Xybrox warbot remote drone designed for hand - to - hand combat . It is apparently Grade - A technology , but is malfunctioning , and can only walk around in circles , hitting itself . Having saved the king ' s life , Hex and Sally are welcome in his court , which has been under attack by a dragon for the previous five days . Hrothgar believes that Sally is a Valkyrie while Hex is her herald . However , they soon realise that Hex is mortal , as he is wearing a bandage on his hand . When the King mentions that he had met another Valkyrie named Asa many years earlier while in the court of King Hrothgar of the Danes , Sally realises that he is Beowulf . His scribe Wiglaf tells them that his father Weohstan travelled with the younger Beowulf across the sea to the kingdom of the Danes . When the younger Beowulf saw the black TARDIS materialising , he believed that its doors were the gates of Valhalla and ran away in shame . As Ace mentions Grendel by name , Weohstan believes that she is the creature ' s mother as she could not have otherwise known his name and draws his sword with the intention of slaying her . In his court many years later , the elder Beowulf tells Hex and Sally that he chopped off Grendel ' s arm which he keeps as a trophy in his throne room . It is in fact the Doctor ' s sonic screwdriver . He then claims that he returned the next day and decapitated the monster . The head is stored in a chest under Beowulf ' s throne . Part three . Lysandra awakens to find herself bound in Garundel ' s ship . He claims that Urodelians have the ability to grow back limbs and that the Doctor is in stasis in the ship ' s regenerative pod . He was attacked by the Xybrox warbot remote drone . After having her thrown into the dungeon , Weohstan tells Ace that he and Garundel have been orchestrating the attacks on Hrothgar ' s kingdom for the previous month . Garundel is a mercenary but prefers the term " speculator . " He has a wager with his swamp brothers to the effect that whichever of them earns the most money with the fewest number of deaths will be given the keys to the mothership . He tells Lysandra that Weohstan dragged him from his ship after it crash - landed in the swamp . He requires inert metals such as gold to repair his ship and has entered into a deal with Weohstan to stage the attacks in exchange for ten kilogrammes of gold . The head which the elder Beowulf has stored under his throne belongs to the Xybrox war - bot remote drone . Sally believes that if they are able to reactivate either the head or the sonic screwdriver , the Doctor will be able to detect the anachronistic technology and locate them . After discovering the white TARDIS , the elder Beowulf recalls seeing the black TARDIS in Hrothgar ' s castle many years earlier . She leads him to believe that Hex and Sally are not gods but demons . Although Wiglaf seeks to test their supposed immortality , the elder Beowulf orders him to bind them until they have defeated the dragon . Ace refers to Garundel as " Kermit " and " Frog Features " whereas Garundel advises her to get a make - over . Part four . Before the bound Hex and Sally can be attacked by the supposed dragon in the elder Beowulf ' s throne room , the black TARDIS materialises around them as well as the white TARDIS , which is still transparent . The " dragon " was in actuality one of Xybrox , a race of cybernetic alien insects , who are tracking Garundel . Following the arrival of Ace and Lysandra in the elder Beowulf ' s throne room , the King tells them after he soon found Garundel hiding in a cave and decapitated him . However , he did not claim his head as a trophy . Lysandra tells him that Weohstan plotted with Garundel to orchestrate the attacks on Hrothgar ' s kingdom in order to make Beowulf a hero . Using the neutron harpoon supplied to Ace by Lysandra , the elder Beowulf kills the Xybrox , which falls over a cliff into the sea . Although he survives by hanging onto the cliff ' s edge , he is gravely wounded and dies soon afterwards . After decapitating Garundel , Beowulf claimed the regenerative pod as a trophy and brought it with him back to his castle . As Lysandra believes that the Doctor has been using her and Sally as shields to protect Ace and Hex , she opens the pod to find Garundel . However , he is soon decapitated once again by Wiglaf , though his head remains conscious . He tells Ace and Lysandra that it was Weohstan , who had been possessed by one of the Elder Gods . It was he who removed the Doctor from the regenerative pod . In return , they place Garundel back in the regenerative pod and send him into space in the home that he will be picked up by his mothership . Having placed the boss from Wiglaf ' s shield on the black TARDIS ' console , it activates a recording of the Doctor ' s voice , who tells them that they are in the wrong TARDIS as the black one will be destroyed in the trip back to the dawn of time . Per the Doctor ' s instructions , they seek refuge in his original TARDIS , which has once again assumed its normal colour . After they enter it , however , the recording continues and the Doctor warns his four companions that if he has not already told them what he is planning , something has gone terribly wrong .