I have a datatable like this:
MtoM
{
   ParentID, 
   ChildID
}
Item
{
    ID,
    Data,
    Label
}
How do I write a linq query that returns every ChildID under a given ParentID and the associated Data and Label for each of these decendent IDs.  If I were using SQL I'd use a union all and inner join, but I don't know linq well enough to do this.
Performance is absolutely not an issue as there will be at most 3 levels of nesting and only 1 or 2 items in each level. The DDL I'm trying to populate is rarely used and is not mission critical.