How do I show employee and supervisor name using join?

I feel I'm so close, but am missing something obviously. I want to get the name of both the employee and supervisor where the name is stored in one table from a different database and the supervisor lookup table references the employee and supervisor id number.
Emp_M                                                           SupLookup
  SID                                                                    SID
  Emp_name                                                      SupID
                                                                            Status
                                                                            EmpJobNum

SID in SupLookup table references the employee, SupID in SupLookup references the supervisor. SID in Emp_M table references all employees (including supervisors).

This is what I have so far:
select b.SupID, b.status, b.EmpJobNum, a.EMP_NAME
from hpsa.[EMP].emp_m a
inner join TimeCardsV3.dbo.SupLookup b
on a.sid = b.SID

This gives me the name of the employee, but not the supervisor. If I call emp_name again, it just gives me the employee name again. I can't figure out how to connect the SupID to the SID without breaking the employee part. What am I missing?