Real Starfleet Heroes: T'Rul
She disguised herself as a Cardassian disguised as a Bajoran on a super deep cover operation.
https://www.youtube.com/watch?v=tKvqhlhXq9s
Totally forgot that was Martha Hackett. I knew she played another character besides Seska, but thought it was also on Voyager.
Totally not a Romulan operative dressed like a Cardassian operative dressed like a Bajoran Maquis who gets absorbed into a Starfleet crew who bails for the Kazon.