Mick finds out Mara cheated for him and falls out with her. Amber discovers a secret message written behind the wallpaper - "Help me, Sarah Frobisher Smythe." Fabian, Nina, and Amber record the cylinders onto a Dictaphone. The young girl on the recordings mentions a murder. They suspect that the girl may be a young Sarah. Amber and Nina go to the old people's home to visit Sarah and confirm that she is, in fact, the girl from the recordings. Amber comes up with a name for their gang - "Sibuna" (Anubis backwards). They make it official with a ceremony by the woods after which Fabian manages to open the puzzle piece, revealing a riddle. Meanwhile, Jason finds Joy's broken mobile phone at the school bins; he searches for more clues but finds nothing. Guest Star: Francis Magee (thetvdb.com)