I'll wait to comment save this...the RMT had more than one "twins" episode and some of them were kind of, er, different ("An identical murder" wasn't bad, but somehow the ending felt just a bit "forced" (for lack of a better word), and while I'm not the brightest bulb in the chandelier I've never quite gotten the ending of "Two plus two equals death").

THIS episode, however, was penned by Ian Martin (still one of and perhaps my favorite RMT writer) and has the richest (IMO) character development one could ask for in a show this length. Again IMO this is the best "twins" episode the RMT ever produced (that I've yet heard).