In the climactic ending of 'Twice Born', Sister Theodosia's ability to shapeshift dramatically alters the landscape of House Harkonnen's political games, revealing hidden layers of espionage and deception. Vayla's interaction with what she believes is her brother, but is actually Theodosia in disguise, emphasizes how this power has been a persistent yet unacknowledged facet of Dune's universe that opens up myriad new storytelling avenues.