Darth Plagueis is a Muun Sith Lord, Palpatine's master. He is the last link but one in the chain Darth Bane started, and he sits at the far end of the Rule of Two. He entered the franchise not as a character but as an anecdote: the opera-house monologue in Revenge of the Sith (2005) in which Palpatine tells Anakin Skywalker about a Sith Lord so powerful he could keep the people he cared about from dying, and who was killed in his sleep by his own apprentice.
Luceno's novel
James Luceno's Darth Plagueis (Del Rey, 2012) turned the anecdote into the best-regarded Sith novel ever published. It gives him the public identity of Hego Damask, a Muun financier of Damask Holdings, and it stages the Sith conspiracy as decades of corporate and political manoeuvring: leverage, holdings, the Trade Federation, and a young Naboo politician spotted early and cultivated patiently.
Midi-chlorians, seriously
The novel's other achievement is taking Plagueis's actual research seriously — a Sith Lord conducting sustained, methodical experiments on the mechanics of life, and getting results, and being unable to replicate them. It reframes the film's throwaway line as the culmination of a genuine scientific programme, which is a far stranger and better idea than "evil wizard".
Legends and canon
The film reference is canon; Luceno's novel is Star Wars Legends. Current canon has confirmed Plagueis existed and taught Sidious, and the 2024 Disney+ series The Acolyte showed him on screen, but no canon work has replaced the biography. His Legends given name and homeworld are not canon and are labelled as such here.
Reading note
Read it immediately after any Palpatine-centred prequel book. It is the connective tissue the films assume and never show.
