Feldman's addition to the cast was kept under wraps as long as possible. Showrunner Matthew Weiner is notoriously spoiler averse. The actor previously appeared as guardian angel Fred on Lifetime's "Drop Dead Divas."
"As Sterling Cooper Draper Pryce tries to build upon its current business, Peggy is given new responsibility. Don and Harry indulge a client," reads Sunday's episode description.
We're going to connect the dots and guess that Feldman's character may have something to do with Peggy's new responsibility.