Dark star alloy was a material that "[g]oes through armour plating like a knife through people." "[I]n the olden days on Gallifrey", the Doctor gave the Master a brooch made out of dark star alloy. (TV: The Witch's Familiar)
Dark star alloy was a material that "[g]oes through armour plating like a knife through people." "[I]n the olden days on Gallifrey", the Doctor gave the Master a brooch made out of dark star alloy. (TV: The Witch's Familiar)