An alien evil threatens the fun-loving, dual-gendered inhabitants of Merculian. Marlo can feel it. Young people are getting sick from alien party drugs, a valuable antique painting is stolen, celebrated dancer Eulio is receiving menacing notes from a stalker and a body is discovered in the Pleasure Gardens. Meanwhile super star Triani's young sibling Rio falls for a mysterious Merculian youth with ties to the notorious River District. Even the dancers are having problems and during rehearsals for the new production of The Night Bird one of them has a serious accident.

Then on opening night, Eulio disappears. Marlo and the Regulators work franticly to find him and in the process discover dark secrets linking to the ruthless Terran criminal and his gang who have taken possession of the River District. But can Marlo or Beny and the secret government group he has joined act quickly enough to save their beloved city?