Irene and Joe's previous cases come to a head when Mr. Cullens of British Intelligence pays a visit to Baker Street. He tasks the pair with scoping out the wedding of the son of one of the biggest companies in London to ensure no harm comes to him during the upcoming ceremony. Mr. Cullens is worried that the mystery woman with the A.B. initials Irene has been unknowingly playing tag with will disrupt the wedding and cause undue trauma to this innocent family. As Irene and Joe dig further into the bride and groom though, they discover secrets that the happy couple would prefer to keep quiet, and reasons for someone wanting each of them out of the picture-for good. With meddling, often come trouble, and it isn't long before Irene and Joe are deep in a twisted web of lies and deception that they struggle to escape. Tension runs high between the pair and puts them in grave danger while threatening to disrupt the friendship they've worked so hard to build.