Travelling many centuries into the past, Helen, Terry and Phil arrive in a cave at the time of the Winter Solstice; here they encounter an old druid who appears to be Rothgo, but whose memory has been scrambled by a curse. On seeing Phil’s black skin the druid instantly proclaims the boy to be ‘the dark warrior’ who it is prophesied will challenge Cynon, the spoilt tyrant who has usurped Rothgo’s throne as high priest of the druids. However, Cynon’s sponsor is an evil woman named Iliac – who is in fact Belor in disguise; when she recognises the children Belor quickly traps them inside a cave, while her future self seeks out Rothgo and engages him in a deadly battle in the night skies. But Rothgo is able to stall Belor, allowing the three children to escape, say his name, and restore his past self’s memory. With Rothgo’s help Phil must now challenge Cynon – but will he be able to best the powerful dictator and discover the location of the Nidas..?