To get employee:
SELECT E.*, D.*
FROM Employee AS E
LEFT JOIN EmpDept AS ED ON E.EmpID = ED.EmpID
LEFT JOIN Department AS D ON ED.DeptID = D.DeptID
WHERE E.EmpId = @EmpId
To get Deparment:
SELECT E.*, D.*
FROM Department AS D
LEFT JOIN EmpDept AS ED ON ED.DeptID = D.DeptID
LEFT JOIN Employee AS E ON ED.EmpID = E.EmpID
WHERE D.DeptId = @DeptId