Dream case

What would be your dream case for Robin and Strike? Obviously I want the Leda storyline resolved but other that that I would love if a client came to them wanting to look in to a murder where there already is someone convicted for it but the client is convinced of their innocence. I picture the client doing it whithout the knowledge/cooperation of the convicted murderer and the client has noticed something anout the case that just doesn’t fit which will undoubtedly spark Robin and Strikes interest enough to take on the case. Would love to hear your thoughts on this!