Supernatural's Bunker Gets An Incredible Upgrade - But There's A ...

WARNING: The following contains spoilers for Season 15, Episode 14 of Supernatural, "Last Holiday," which aired Thursday, 8 PM ET/PT on The CW.

After a long hiatus, Supernatural's final season resumes with a subdued episode that is mostly free of the mounting, world-ending stakes looming large. While Jack wrestles with his fate as Earth's designated savior (passed onto him by Billie, aka Death), Sam and Dean enjoy a taste of what life could be like if they had a little more domestic help around the Bunker. And not only does their Fortress of Solitude fill up with more homely touches, but it's also revealed to have some hidden gadgets that the Winchesters were completely unaware of. Most notably, "monster radar."

Unfortunately, like almost everything in the hunting family's lives, all good things must come to an end, and the cost for keeping these useful tools is far too high for Sam and Dean to pay: Jack's life.

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Having spent most of their adult lives on the road thanks to their father's monster-hunting, discovering the Bunker was a huge deal for the brothers in Season 8. The underground stronghold was created and played host to the American Men of Letters -- a secret organization that studied the occult and eliminated monsters. Supposedly the "safest place on Earth," the Bunker was left dormant for decades until Sam and Dean rediscovered it, as well as their secret heritage as Men of Letters themselves. But though they've made good use of it as a permanent base of operations, Season 15's "Last Holiday" reveals that they've neglected to explore the structure in full.

When the aging building's pipes play up, Dean hits the reset button in the Bunker's control room. This unwittingly liberates a wood nymph -- who goes by the name of Mrs. Butters -- that once served as the Men of Letters' housemaid. Suspended in standby mode since the late '50s, Mrs. Butters is Mrs. Doubtfire and Mary Poppins rolled into one: a cheery, rose-cheeked disposition that belies cutting criticisms about how "her boys" choose to lives their lives. Naturally, Dean nicknames her "magic Roomba." As well as keeping the Bunker spick and span and whipping up a number of festive banquets to make up for all the Holidays the Winchesters have missed over the years, she uses her magic to get the Bunker up to full power.

Apparently, the Men of Letters' base hasn't been operating at full capacity. With the wood nymph's upgrade, the table map at the hub of the Bunker can now track and trace monster activity -- alerting Sam and Dean straight away to the exact nature and whereabouts of each case. This makes the Winchesters more efficient than ever. (They also gain access to an interdimensional geoscope but, following Chuck/God's multiversal destruction, the view ain't so great...)

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Unfortunately, Mrs. Butters doesn't embrace the Nephilim that the current Men of Letters are keeping under close watch. Following Jack's accidental banishment of Mary Winchester, Lucifer's son is still wracked with guilt. His new guardian isn't so sympathetic. Convinced that Jack will only turn on the rest of his found family, she plies him with power-sapping smoothies, handcuffs him and tries to persuade Sam and Dean to kill him like they would any other monster. Eventually, after her violent Professor Umbridge-esque meltdown, Dean convinces the rogue nymph that Jack's destiny is to save the world, not destroy it, and she backs down. (Just as well considering she slaughtered 200 Nazis during WWII in one go.)

Setting her free to return to the woods means the loss of the monster radar, which Dean is less saddened by than he is by the loss of homecooked meals and freshly-done laundry every day. There's no reason why the Winchesters can't find an alternative method of getting the Bunker back up to 100 percent again. But, with far more pressing matters at hand, restoring it may have to take a backseat for now.

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