John Constantine arrives back in London to find Gary Lester in his bath swarming with bugs. Lester was in Morocco where he performed an excorcism only to get possessed himself by the demon Mnemoth. Constantine goes to Africa to find out more about this demon and how to fight it. He then goes to New York City taking Gary Lester with him to visit Papa Midnite. The demon Mnemoth is running loose in the city and Constantine finds help from the ghost of Emma (see Swamp Thing #37).
The segment of this story in which Constantine puts Lester under to find out what happened in Morocco was related in a six page preview inside Swamp Thing #67.