[3.5] Investigating A Noble House

[tahu88810]

So in an upcoming session of D&D, my players will be hired to dig up some dirt on a noble House. So far, I've decided that there are two major things to find out: House Borsail is led by vampires, and they're taking part in the slave trade (likely with connections to Skullport, since this takes place in Waterdeep).
The obvious thing is to progress from learning about the slave trade to learning about vampires (ie. some of the slaves are taken by the higher ups of the noble house, and those spawn that attacked earlier were most certainly some of the missing slaves).

Now, the big issue is the fact that the party consists of a Scout and Beguiler. So they'll want to be stealthy about this. Do you have any suggestions as to how this might go down? They're level 11, so I can't imagine the common household guard would notice them.

[Dust]

Where do the Vampires sleep during the day? As soon as you've decided this, you know where the party will discover an abnormally large amount of security - magical wards and possibly even sleepless watch-constructs, whatever the obviously-wealthy vamps can afford to protect themselves at their most vulnerable state.

As soon as the PCs discover where all the security is centralized, you can determine exactly where they'll go first...as well as what might be waiting for them.