Wibble & Pplimz, the Crucible's most unusual private investigators, must set off from their office in Hub City to clear the name of a former client. Along the way, their investigation broadens from a simple accusation of theft to include a missing person, a potential murder, and a highly unusual gem. Four interlinking incidents take them across the Crucible, as they attempt to solve the case. But there's something more sinister lurking underneath: evidence of a secret society that aims to discover the power of the Architects, and forever change the nature of the Crucible itself.