The Book of Shadows ( short story ) The Book of Shadows was the sixth story in the anthology " Decalog " . It was written by Jim Mortimore . It featured the First Doctor , Ian Chesterton and Barbara Wright . Summary . 331 : Rhakotis ' ship crashes on a watery planet , and he thinks he is going to die . However , he survives the crash , though injured , and hopes that where there is water , there is intelligent life . 322 : The TARDIS is caught in a rockfall in a mine . The Doctor and Barbara escape , but Ian is trapped inside . Barbara sees some slaves mining , and asks for their help digging Ian out . They recognise her , however , and one man , Susa , mentions Alexander ' s coffin and asks her where her guards are . Thinking quickly , she says they are not with her . Susa attacks the Doctor but the Doctor defeats him easily , knocking him out . Barbara tells the rest of the slaves that if they help her , she will free them . An Israelite slave named Aristea takes some men with him to dig out the TARDIS . The Doctor scolds her for interfering with history , but she knows when they are , and in history , the slaves really were freed by Ptolemy Lagus . They notice that Susa is gone . He has sneaked out to fetch guards . However , when the guards , led by Arrhidaeus , arrive , they recognise Barbara and kneel to her . Arrhidaeus has Susa killed , and makes the camels ready for travel back to Alexandria . 331 : Barbara finds herself in a crowd of people . She recognises Aristea , who is being stoned . When she intervenes , she is stoned by the crowd , but is rescued by Ptolemy Lagus . She tells him she has lost her memory . 322 : Barbara and the Doctor accompany Arrhidaeus to Alexandria . Barbara has explained the Doctor as a scholar who is interested in craftsmanship . Barbara explains to the Doctor that they are in 322 or 323 BC , and Alexander the Great has just died . The slaves were mining gold for his coffin . Ptolemy Lagus is now the king . As they near the city , a young boy rides out to meet them , and greets Barbara , calling her “ Mother ” . At the city , they are greeted by Ptolemy Lagus , who , to Barbara ' s surprise , sweeps her from her camel ' s back and embraces her . 331 : Ptolemy carries the injured Barbara to safety , but notices that a crowd has gathered near the harbour . Rhakotis ' spaceship has just crashed , and the crowd urges a fisherman to kill the alien . They are stopped , however , by Barbara ' s pleas not to hurt him , as he is asking for help . 322 : Barbara explains to Ptolemy who the Doctor is . She then speaks to Ptolemy about the slaves in the mines . He asks a question , to which a feminine voice answers . It is Ptolemy ' s wife , who Barbara realises is an older version of herself . The older Barbara , on seeing the younger version , faints , while Ptolemy laughs at his little joke of bringing the two women together . Ptolemy tells Arrhidaeus to free the slaves in the mine . He asks Barbara for suggestions on what to do with them . She suggests the older slaves work as scholars or clerks and the younger , able - bodied slaves should join the royal army . The Doctor again scolds Barbara for interfering in history , saying that Ian will be impressed into the army . He also points out the existence of the Pharos Lighthouse , which was built by Ptolemy Philadelphus – Barbara ' s “ son ” , who at this time is only eight years old . The Doctor tells her history is being rewritten , and he heads to the library to see what he can find out . 331 : Alexander wants to use Rhakotis to further his ambitions , but Ptolemy suggests that , with Barbara as interpreter , Rhakotis is willing to offer his knowledge in exchange for gold , which he needs to repair his ship . Barbara tells them that Rhakotis needs to construct a diving bell to conduct repairs on his ship below the water ' s surface . 322 : At the palace , Arrhidaeus tries to assassinate Ptolemy on Perdiccas ' behalf , but Ptolemy kills him instead . Meanwhile , the two Barbaras talk . The older Barbara doesn ' t remember who she is , but the younger Barbara wants to know how she ends up going back in time eight years . Ptolemy suddenly enters with Philadelphus , telling the two women that he has been betrayed . Perdiccas is in control of the army . He tells them to lock themselves in while he goes to the library to ask for Rhakotis ' help . The younger Barbara leaves to find the Doctor . It is raining . Outside the library , she collides with a man who is holding a book — not a scroll . She tries to take it from him and he resists . Soldiers are making their way through the city , and people are running and screaming . Barbara grabs the book from the man and runs into the library . Suddenly the people and soldiers are gone , and it isn ' t raining any more . 331 : Barbara notices little differences in the library , and realises she has just travelled through time . She hears a loud noise , and running outside she sees a spaceship about to crash . She runs towards it . 322 : At the library , the Doctor overhears an argument between Aristophanes and Eratosthenes . He can ' t help sniggering , and when they confront him , he informs them that their lives are supposed to be three centuries apart . They are aware of this , and tell the Doctor that there are time portals in the library , installed by Rhakotis . Aristophanes shows the Doctor a scroll , which , on seeing the title , he snatches away . He must find the original , which Aristotle has . He sets off in search of it . 331 : Ptolemy and Barbara watch as Rhakotis and Alexander submerge in the diving bell . 322 : The older Barbara sees Rhakotis ' spaceship taking flight , and suddenly her memory returns . She leaves Philadelphus and runs to Rhakotis ' rooms . Ptolemy is demanding that Rhakotis use his technology to help defeat the army , but Rhakotis ' ship is barely staying aloft as it is . When Barbara enters , Ptolemy demands why she left their son , and then acknowledges himself betrayed , as his son is most likely dead now . He tries to kill Rhakotis , but soldiers enter and one soldier fights with Ptolemy . They kill each other , and Barbara is horrified to see the soldier is Ian . Rhakotis ' ship cannot stay aloft any longer and crashes into the city . The Doctor arrives to find Barbara and Rhakotis , and gives them a book that can help them rewrite these events . If they do , Rhakotis will die and Barbara will no longer have a son and husband . The Doctor leaves it up to them to decide . 331 : Rhakotis ' ship crashes on a watery planet , and he thinks he is going to die . He barely remembers the temporal explosion , then he dies .