Entity Framework How can I filter my results using a navigation property?

I have a legacy class database which is represented by the following model.

public class Course
{
    public int Id { get; set; }
    public string Title { get; set; }
    public string Description { get; set; }
    public CourseLevel Level { get; set; }
    public float FullPrice { get; set; }
    public Author Author { get; set; }

    public IList<Tag> Tags { get; set; }
    public IList<Attendee> Attendees { get; set; }
}

public class Attendee
{
    public int Id { get; set; }
    public int StudentId { get; set; }
    public decimal Tuition { get; set; }

    public Student Student { get; set; }
}

public class Student
{
    public int Id { get; set; }
    public string Name { get; set; }
    public string Address { get; set; }
}

public class Author
{
    public int Id { get; set; }
    public string Name { get; set; }
    public IList<Course> Courses { get; set; }
}

public class Tag
{
    public int Id { get; set; }
    public string Name { get; set; }
    public IList<Course> Courses { get; set; }
}

      

        
        
        
      

    

I need to get a list of classes that either part of the course name or description or part of the student name matches my search string. The first part is simple.

List<Course> courses = db.Courses.Where(w => w.Title.IndexOf(searchString) > -1 || w.Description.IndexOf(searchString) > -1).ToList();

      

        
        
        
      

    

How do I filter against w.Attendees.Student.Name now?

I tried:

List<Course> courses = db.Courses
    .Where(w => w.Title.IndexOf(searchString) > -1 || 
           w.Description.IndexOf(searchString) > -1 ||
           w.Attendees.Any(a => a.Student.Name.IndexOf(searchString) > -1)).ToList();

      

        
        
        
      

    

And it just returns an empty list.

I'm still new to Linq, I am originally from Grails. Any help is appreciated.