I set this up to use bold, and the code is correct, but for some reason the McCoy line about oxygen atmosphere, doesn't come out right. It shows as italics not bold, and with extra asterisks showing. Why is that?

KIRK: All right, how about this? A creature that lives deep in the planet below us, at home in solid rock. It seems to me that in order to survive, it would have to have some form of natural armour plating.

SPOCK: It could explain much, especially since the colonists are armed only with phaser one.

KIRK: But our people have phaser number two.

SPOCK: Which I could adjust to be more effective against silicon.

*MCCOY: Silicon-based life is physiologically impossible, especially in an oxygen atmosphere. *

SPOCK: It may be, Doctor, that the creature can exist for brief periods in such an atmosphere before returning to its own environment.

MCCOY: I still think you're imagining things.