To clever for your own good eh? That's too bad. And also a classic outcome, players ignoring your juicy plothook and going another way entirely.
It will all work itself out. There's still a body that needs identifying and the PCs chose the route of torturing and killing a Xanathar Guild enforcer for what answers he could give, so that propels the plot forward in its own bloody way. Plus, now I have an easy way to get the weirdo demon worshipping nobles involved: I am going to have them be the ones that wanted a nice adventure mind trip at the Memory Den. Now they know who the PCs are and they know who the body is.
