@d-sel .... they got them from the Klingons. There was some form of alliance/agreement to share technology between them as they both saw the Federation as the bigger thread. And both sure were planing how to get rid of each other afterwards I'm sure.
Granted, those facts were established later. But I still think it works for this episode. It adds a bit of mystery.
Shout by D.seLBlockedParent2021-09-15T21:27:58Z
The Romulans had Klingon ships because.......?