On the Season Four premiere of The Flash, Barry returned from the Speed Force, but he wasn't exactly himself. In addition to speaking complete gibberish, the speedster was also scrawling a strange cypher on every flat surface he could get his hands on.
While Cisco attempted to decode the message, all he came up with was "This House is Bitchin'," a seemingly throw-away phrase of nonsense that even Barry couldn't assign meaning to once he was back to his old self. Of course, as fans of The Flash have been seeing slowly play out over the first half of the season, not everything from Barry's fresh from the Speed Force "A Beautiful Mind phase" has been without some meaning or connection. The symbols Barry was scrawling on walls match to symbols on The Thinker/Clifford DeVoe's cheek and the knuckles of Caitlin's boss at the bar and while many of the members of Team Flash have had a bit of fun dropping variations of "this house is bitchin'" throughout the first half of the season, we have to ask: is there still more to the nonsense phrase and, if so, where will those answers come from?
As for whether the phrase is going to be revealed to have some important meaning or something significant behind it, it's probably fairly safe to say that there is more than well-placed humor to the curious phrase. One thing The Flash does and does well is layer clues and pick back up on previous story threads, especially when it feels like perhaps the show has moved on. With the mystery symbols having taken up so much of the season premiere only for their assumed meaning to be turned into more of an in-joke for Team Flash, it feels like both the characters and the audience are being set up for a larger or more significant reveal. Additionally, now that Caitlin's side storyline with Amunet Black has somewhat merged into the primary storyline involving The Thinker -- after all, DeVoe did get his "new" body by buying a bus meta from Black -- The Flash might finally be in a position to start unravelling some of those threads from the premiere. This is especially true now that Barry finds himself heading to trial for DeVoe's supposed murder, a plot that echoes the classic comic book story arc "The Trial of the Flash."
It's also the show's turn towards "The Trial of the Flash" that could lead us to where we will get answers for what "This House Is Bitchin'" means. While the symbols are not exactly the same, they are like the symbols that make up Interlac, a language that in comics is referred to as the "intergalactic universal language of the 30th century." Fans of Supergirl have already seen Interlac a few times in the series, first in graffiti seen on the alien bar and then again on the pods in Mon-El's Legion of Super-Heroes ship. With the comic book "The Trial of the Flash" arc leading to Barry running into the future -- the 30th century to be exact -- the comic version of Barry Allen would have no doubt have come into contact with the language. If the idea that, instead of being "stuck" in the Speed Force Barry actually ran into the future turns out to be true -- or even some variation where Barry experienced the future while in the Speed Force without actually having traveled there -- the cypher Barry is scrawling in the premiere could be a badly remembered version of Interlac, or potentially even one modified for use on the Arrowverse television shows. In that case, the mystery girl from the wedding might hold the key to translating the cypher as both Jenni Ognats and Dawn Allen have ties to the future and would, in theory, be able to read Interlac.
All theories about the phrase aside, one thing we do know for certain is that everything we saw in the season premiere matters. Grant Gustin told ComicBook.com last month that everything Barry said at the beginning of the season is important.
"He was talking all over the place and elements of that will show up throughout the season and may already have," Gustin said. "We'll circle back I would imagine at some point this season and connect all of them for you. But yeah that was all very important, everything he said at the beginning of the year."
The Flash will return on Tuesday, January 16, 2018 at 8/7c on The CW.