Goliath's shocking identity revealed on 'Resident Alien' - so let's break down exactly what that means

Great Scott! Last night's episode of Resident Alien changed the game forever. Everything we learned in the first half of Season 2 has been reframed with the major reveal that Doctor Harry Vanderspeigle (Alan Tudyk) and New York street artist Goliath (David Bianchi) are not different members of the same alien species, but actually the same exact person! ... or alien, rather.

How is such a thing possible? Well, the answer comes down to one of the oldest sci-fi tricks of the trade: time travel. Sixty years in the future, our home planet lies in ruins. Human civilization and nature have both collapsed in the wake of a terrible invasion from an advanced race of malevolent extra-terrestrial beings so fearsome, they make Harry's people look cute and cuddly by comparison.

With his human body starting to grow old and useless, the fake Dr. Vanderspeigle returns to alien form, roaming the post-apocalypse for hundreds of years, searching for a way to save a planet he once sought to destroy. After six centuries, he comes across a trans-dimensional portal that allows him to step back in time. "Of course they left these behind," Harry states in voiceover. "I must be on one of the planet's energy lines. Humans called them 'ley lines.' If there is one portal, there will be more. Then I can change all of this"

The theory goes that certain manmade landmarks (such as the Great Pyramids of Giza and Stonehenge) are connected by invisible currents of energy. It's a major tenet of those who believe that early humans were visited by aliens and instructed to build these wonders of the world, which serve a greater purpose beyond just looking cool. While the show has yet to provide a firm answer on what it all means, Harry's internal monologue seems to hint that the alien conquerers may have tapped into these ancient ley lines as a way to conveniently transport their armies and ships to Earth. Once the carnage was over, they simply left the doorways open. Again, this is all just conjecture right now.

What we do know is that Harry finds a specific portal, walks through it, and into the Brazilian rainforest 33 years before his crash-landing in Colorado. His shocking appearance accidentally leads to the death of a local man (Bianchi), prompting Harry to take his form, which leads to the creation of a causality loop, which is one of the most famous paradoxes in all of pop culture.

It's like Harry and Hermione going back in time to save Sirius and Buckbeak in Prisoner of Azkaban — nothing about the timeline is severely changed because it was always meant to happen. Harry (Vanderspeigle, not Potter) now knows what he must do: go to New York and become the artist known as Goliath. He will fully assimilate into the human world, become a famous street artist, mate with Violinda Darvell (Maxim Roy) and leave a warning for his past self via his alien offspring.

Mind=blown.

New episodes of Resident Alien air on SYFY every Wednesday at 10 p.m. Eastern before hitting the SYFY app and Peacock the following day. Only four more episodes of Season 2 remain, but don't worry — the hit show has already been renewed for a third season.