Getting NHibernate session to see uncommited, external ADO.NET changes within TransactionScope

Question

I have some code that does something like this:

public void DoDatabaseWork()
{
   _repositoryIDontControl.SaveSomeStuff(objectThatNeedsStuff.Stuff);

   using (var session = ... )
   {
      session.Save(objectThatNeedsStuff);
   }
}

The crux here is that within my NHibernate mapped data model I have an object that references another object from a library that is not mapped using NHibernate. So before I save my object using the session, I need to separately save this non-Nhibernate object (that's implemented in a different dll library) via a repository that's in a separate dll.

Is there anything I can do to make my session see these objects (so the foreign key constaint isn't violated) if I'm doing both of these within one transaction scope? Or should I give up on using NHibernate for my data model if I need to reference an object that's not mapped within my project?