Mary Tamm is a very busy woman in this story, playing no less than four different roles - Romana, Princess Strella, and each woman's android double. Truth be told, of course, the quartet of performances seldom stray from each other, mostly because Romana, like the Princess, is a posh, privileged princess...or at least acts like one.
The story's only death occurs in this episode when Madame Lamia is shot down by accident by one of Count Grendel's guards. It's the end of what is really a sad subplot. It's established early on that Lamia has feelings for her master, Grendel, and that, at one time, Grendel may have felt the same towards her. Later, when Romana tells her that Lamia will never have Grendel for herself, and that the Count is just using Lamia for her skills with androids, a clearly hurt Lamia replies, "I know. But it is better than nothing."
Even up until just before her death (after the Count gives her a tantalizing, and misleading, kiss), she is tempted to take The Doctor's offer of safe passage for both the Count and Lamia. And then, after the attempt to kill The Doctor fails, Lamia dies. And, by the way the sequence is cut together, I'm not entirely sure that guard wasn't aiming right for her when he fired his fatal bolt.
Finally, in keeping with the little things I'm noticing about this story, keep your eyes fixed on Tom Baker during the scene late in this episode where the Count is offering The Doctor the throne of Tara. The scene lasts at least a minute, and yet Baker doesn't blink once. In fact, he keeps a rigid, wide stare on Peter Jeffries for almost the entire duration. Kudos to Baker for just being so alien, but credit Jeffries, too, for not cracking up during the scene because of Baker.