The previous episode in this scorching series, Killers of the Dawn, ended with Darren's despair after Mr. Crepsley was killed and the identity of the Lord of the Vampaneze finally revealed. The Lake of Souls, opens as Darren and Harkat hunt a black panther - they spring a trap, but their prey springs back - and then the story flashes back six months to the time when they escaped from the tunnels.They're met by prescient witch Evanna, who tells them there is still one more chance to defeat the vampaneze, and offers Darren's beloved Debbie Hemlock and police Chief Inspector Alice Burgess the chance to disengage from the war and return to their old lives. Vancha March returns to Vampire Mountain, while Darren, accompanied by Harkat, seeks refuge from his grief with his old friends at the Cirque Du Freak. There, Truska gives wise advice - 'The death of somebody you love is the second worst thing in the world ... Worst thing is letting it hurt you so much that you die too - inside.'When Harkat's nightmares return, he and Darren set out on a quest, with Desmond Tiny pulling the strings. He sends them to a 'barren, monster-filled wasteland'. 'One crisis at a time', they have to kill the panther, steal from an enormous toad guarded by alligators, fight off dragons, milk a monster for its explosive venom, and reach the Lake of Souls. At each stage there are puzzles to solve and key items to collect. Harkat's identity is quite a surprise, and the episode's ending injects a terrifying new twist in the series, one that will make fans anxious for #11, Lord of the Shadows.