WARNING: The following contains spoilers for Star Trek: Discovery Season 3, Episode 7, "Unification III," now streaming on CBS All Access.
Through seven episodes of Star Trek: Discovery's third season, the biggest mystery has been "The Burn," a mysterious catastrophe that destroyed vast amounts of warp-capable ships. However as fans find out more about the events leading up to "The Burn," more questions seem to emerge, and Discovery's latest installment has answered at least one of them.
When Michael Burnham and crew first arrive in the 32nd century, capitalism has re-emerged and focused around one thing: dilithium. According to Michael's findings, over 700 years after Discovery made the jump through the wormhole, supplies of the important mineral began to dry up. The Federation attempts multiple alternate plans of transportation to alleviate their dilithium dependency, but then "The Burn" happens, destroying all dilithium across the universe in an instant.
Up until this point in the season, the reason behind the dilithium scarcity remained shrouded. Enter T'Rina, president of Ni'Var, the planet of the newly-unified Vulcans and Romulans. As she coldly greets the crew, she fills captain Saru in on what caused them to leave the Federation over a century ago, and it all connects back to dilithium.
According to T'Rina, the shortage came from the growing number of planets entering the Federation. Starfleet consisted of about 350 different planets at its peak, according to its current leader Admiral Vance. Enlisting so many ships for the fleet meant shelling out the dilithium to make them warp-capable. It seems that the supply outweighed the demand, and the Federation's need to create new ships outpaced its ability to harvest and provide the dilithium.
Needing to solve a problem they caused, Starfleet turns to its growing membership to create new means of transporting ships. Ni'Var's project is SB-19, which uses an experimental system that could warp ships in an instant. Despite the planet's protest at its danger, the Federation moves ahead with it. As a result, Ni'Var believes they were responsible for "The Burn" and pulls out of Starfleet.
Star Trek: Discovery has shown the Federation at its low point, fractured and attempting to put out a hundred different fires at once. The tragedy of their current situation comes from their prior ambition. Because Starfleet is eager to accept so many members, it unintentionally puts a pressure on one of its most vital elements. While it's unknown as to what caused "The Burn," a piece of the puzzle has been filled in.
Streaming on CBS All Access, Star Trek: Discovery stars Sonequa Martin-Green as Commander Michael Burnham, Doug Jones as Commander Saru, Anthony Rapp as Lt. Commander Paul Stamets, Mary Wiseman as Ensign Sylvia Tilly, Wilson Cruz as Dr. Hugh Culber, David Ajala as Cleveland "Book" Booker, Blu del Barrio as Adira, Ian Alexander as Gray, Tig Notaro as Chief Engineer Reno and Michelle Yeoh as Philippa Georgiou. New episodes of Season 3 air on Thursdays.