I am having a bit of trouble figuring out how to make a specific design in fluent nHibernate. I have a small workflow prototype with two aspects to it. First, you can design a workflow, that has a collection of 'phases' and a phase has a collection of 'Tasks'. I have this part loading and saving using nHibernate. Second part, these workflows will be used in an engagement class. Every engagement of type X will use the same workflow. I have created a class called 'Engagement Task' that inherits from the Task class as it needs the base properties from it, plus a couple of other properties like who it is assigned to in that particular engagement. Now I can load a workflow easily and it loads the phases and tasks because they are set up as HasMany relationships, but what I can't figure out is how to change it to load Engagement Tasks instead of tasks when in the engagement class. Without using nHibernate I would simply join the engagement task table with the task table, but I can't wrap my head around this using fluent mappings. I would post mappings and code but this post would be extremely large, so hopefully this makes enough sense.