Five seasons ago Arrow began, and the last thing DC fans ever imagined was the idea that that humble season would spawn a superhero jam session that would involve time travel, super-powers, aliens, and some of the biggest icons in DC history. But here we are, DC’s four-part crossover that encompasses Supergirl, Flash, Arrow, and DC’s Legends of Tomorrow. And you guys, it was amazing! Who ever imagined the grounded and gritty Arrow could lead to the biggest superhero story ever told on network TV. There were so many fantastic and uplifting moments in this four-parter that it just boggles the mind of any superhero fan. So, let’s break it down and bask in the glory of CW’s “Invasion.”

Supergirl – “Medusa”

1. Red Skies

This week’s Supergirl is really a crossover in name only as the bulk of the episode focuses on issues concerning Supergirl and her world. It reminds one of those old school “Red Sky” crossovers. This term defines a comic that crosses over with a major event but not really. During the era of Crisis on Infinite Earths, some comics had the Crisis label on the cover, but when you cracked open the issue, you’d find a story that has nothing to do with Crisis save for a mysterious red sky. This week’s Supergirl is kind of like that. Which isn’t to say the episode isn’t action-packed. You have Supergirl facing down Cadmus and Cyborg Superman, some startling revelations about Lena Luthor and where her loyalties lie, and so much more. But if you were waiting for any CW superstars to arrive, you’d have to wait until the last few minutes of the episode.

2. Green with Envy

Well, that whole White Martian blood transfusion thing seemed like it was going to be a huge deal. Guess not. A few weeks back, J’onn J’onzz received a blood transfusion from Miss Martian. This revealed that the Last Daughter of Mars was actually a hated White Martian, and now J’onn had White Martian blood coursing through his veins. I was getting ready for a White Martian Jekyll and Hyde thing, but this plot thread is brought to a sudden close this week. You see, Project Cadmus releases an alien virus designed to kill all aliens on Earth (an event that would nicely mirror that conclusion of the crossover). Supergirl and her pals manage to render the virus inert and at the same time, cleanse J’onn of the Martian blood. After a huge build-up, that whole White Martian blood thing is shuffled out the door pretty darn quick.

3. Family Feud

It looked like the mother of Lex and Lena Luthor was going to be the big bad this season, but she too is pushed off the stage this week. With Supergirl’s adoptive father’s whereabouts still a concern and Cyborg Superman still out there, I don’t think we’ve seen the last of Cadmus, but Mrs. Luthor is brought down by her own daughter. For a while, it looked like Lena was going to side with her mother and bring about the death of every alien on the planet. But Lena went against her family legacy and betrayed mommy dearest, leaving fans with the question of whether Lena had broken the Luthor legacy of evil. Somehow, I doubt it.

4. A Legion of Potential

Mon-El continues to be an absolute delight and it’s kind of a shame that Mon doesn’t join Supergirl on the rest of the crossover. I guess the heroes would have been too overpowered if the Daxamite joined the fight, but man, would I have loved seeing Mon-El interact with the rest of DC’s TV heroes. What a Legion that would have been. See what I did there? But there is a bit of an ominous cliffhanger as a group of really creepy looking aliens are on their way to Earth and their target is Mon-El. I guess we have our big bads for the second half of season two after all.

5. Let the Crossover Begin

So after Team Supergirl defeats Cadmus and stops the alien death bomb, Flash and Cisco Ramon vibe over to Supergirl’s Earth and our crossover begins in earnest. Throughout the episode, Cisco’s Vibe gates would pop up and disappear, but it only took one to open and Flash to return to Kara’s world — and now Supergirl is off on her first otherworldly adventure.

The Flash – “Invasion!”

1. Get to the Point

Even though this episode of The Flash has a million guest stars, it’s still Barry’s story as the guilt and recriminations of the Flashpoint are still the central focus of the series. It’s almost as if the invading Dominators are background as the heroes gather and choose Barry as their leader. But the honeymoon doesn’t last as the gathered champions soon learn that Barry messed with time. They turn on him (briefly), but the heart of the episode (and of the whole crossover) is Cisco. Cisco still cannot get past the death of his brother, and this bitterness tempers the whole event.

2. It’s Supergirl’s World, We Just Live in It

Supergirl is the stand-out star of this episode of The Flash and of the entire “Invasion” event; this is the first chance to see Kara interact with the rest of the DCU. She met Flash last year, but the moments she shares with Felicity, Diggle, Mick Rory, and Oliver Queen himself are absolute delights. Even though she smiles her way through the episode, viewers get a sense that it’s a brand-new day when it comes to being a powerhouse now that Supergirl has arrived. This fact is driven home during a training exercise as Supergirl easily defeats Team Arrow, Team Flash, and the Legends of Tomorrow — without losing her smile.

3. Meanwhile… at the Hall of Justice

Fans of a certain age will have a joyful nerd prolapse when they see the building that the gathered heroes use as a training grounds and as a headquarters. On the inside, this locale is a STAR Labs warehouse, but outside, the facade matches one of the most famous locations in superhero lore: it’s the Hall of Justice from Super Friends. In live-action. On TV. That gift, that wonderful Easter egg, is one of the countless reasons to love DC TV. Greg Berlanti, Andrew Kreisberg, Geoff Johns and the rest of the DC TV brain trust certainly know their roots. I swear you can almost hear the phantom voice of Ted Knight- “Meanwhile…”

4. Domination

As far as the villains are concerned, the Dominators are suitably creepy. You don’t see much of the Dominators during the episode, but the glimpses you do get her nightmarishly effective. I do kind of miss the flowing robes from the comics, but the Dominators do have those nasty teeth and those big red dots on their heads, so the design stays close to the source material. It is revealed in this episode of The Flash that the Dominators have visited Earth before in the 50s as things get all sorts of classically sci-fi up in here.

5. The Kid’s Alright

As I said, despite all the superhero guest star shenanigans, this is, at heart, an episode of The Flash. Iris, Joe, Cisco, HR, and Kaitlin all have major roles, but Wally West takes center stage as he continues his journey to become Kid Flash. Joe and Iris are more than reluctant to let the inexperienced speedster battle the Dominators, but when Barry falls in battle, Wally springs into action It’s one of his first superhero battles, and it’s against a legion of aggressive aliens — not bad Wally. Wally does get injured in battle, so HR Wells agrees to train the future Kid Flash, so look for this episode to have many future repercussions as far as Wally West is concerned.

Arrow– “Invasion!”

1. Roots

This week’s crossover episode of Arrow, serves as a constant reminder that all this DC TV awesomeness began with Oliver Queen and his decision to become a masked crusader. All the super-beings, aliens, super-villains, time travel, monsters, and costumes sprang from Oliver Queen and Arrow. It’s hard to believe that a show that started with no codenames or powers morphed into a functioning universe of just about every DC hero one can imagine. Oliver began fighting drug dealers, but here we are, one hundred episodes later, and Oliver is fighting CGI aliens and flying on a time ship. And somehow, it all seems very natural and organic.

2. Times Past

This week’s Arrow happens to be the one-hundredth episode of the series, and “Invasion!” is a love letter to those times past. This week, Oliver, Diggle, Thea, Sara Lance, and Ray Palmer are held prisoner aboard a Dominator ship and probed for information regarding Earth’s metahumans. To keep the heroes docile, the Dominators put the heroes in a pleasant dream world where loved ones are still alive. So this week sees the return of Oliver and Thea’s mom and dad and the return of Laurel Lance.

Seeing Laurel as Oliver’s bride to be really makes me miss the character. Plus, being able to resist the dream world and finding their way back to reality to battle the Dominators proves what amazing heroes Team Arrow consists of, even though none of them possess powers. At its center, the one-hundredth episode of Arrow is a tribute to all those we’ve lost in the Arrowverse and all the adventures we have shared.

3. The New Team Arrow

While Oliver and company (HA!) were aboard the Dominator vessel, Felicity, Wild Dog, Mr. Terrific, and Ragman kept the fight going at home. But they had help. To find Oliver’s location, Felicity needed a recently invented device that had been stolen by a new villain named Cyber Woman. That may have been tough for the group of neophyte heroes, if Flash and Supergirl didn’t lend a hand. Barry and Kara springing into action and easily defeating this villain of the week gives fans an idea just how powerful Barry and Kara are as they take down the powerful Cyber Woman in seconds flat. While high-fiving. It is awesome.

4. Mercy

Did Oliver’s dream world remind anyone else of the classic Superman Black Mercy story? You know, the classic Alan Moore jam where the villainous Mongul attaches a Black Mercy flower to Superman and forces the Man of Steel to live out a beautiful dream of a Krypton that was never destroyed. To come back to reality, Superman had to destroy his dream world and dream family, and this week, Team Arrow have to make an identical choice. To return to fight the Dominators, Oliver and friends have to turn their back on very real versions of Oliver’s mom and dad and Laurel. It is just brutal and heart-wrenching as it was for Superman in Moore’s classic tale.

5. Flying High

So a series that began with a hooded vigilante fighting drugs runners and gun thugs in back allies continues with a swashbuckling rescue of the same hooded hero by a time ship. Can you think of any other series that began immersed in reality, but by episode one hundred, has introduced every fantastical element of genre fiction? That’s “Arrow,” and that’s why we love it.

DC’s Legends of Tomorrow– “Invasion!”

1. Worthy of the Big Screen

Don’t let anyone tell you differently; this episode of DC’s Legends of Tomorrow, the final episode of the “Invasion!” crossover, was just as huge in scope and exciting as any superhero film. This might be the most superheroes ever put into live-action as Team Arrow, Team Flash, and Supergirl all gather to finish off the Dominators in a story that spans decades. It is just as big and bold and in your nerd face as any superhero film, and it is something this superhero nerd never experienced on prime-time TV.

2. New Kids

This episode finally allows Steel and Vixen to shine as they play pivotal roles in saving Team Arrow and going back in time to discover the origins of the Dominators. Steel in particular proves he can play with the big boys as he not only rocks his new costume, he takes a leadership role as the Legends and Cisco travel to the past and discover the purpose of the Dominator attack on Earth.

3. Heart and Soul

This is DC TV, so you know there’s more going on than just punchy-punchy. This week, we meet Martin Stein’s daughter, a woman created because of Stein’s meet-up with his past self. Thanks to this time meddling, Stein now has a daughter he doesn’t know and he must work with the brilliant woman (who looks like a young Margot Kidder) to design technology that can stop the Dominators. So, with the non-stop action of this crossover finale, we also have some big-time feels as Martin Stein must learn to love a woman he never knew. We also get some bonus Firestorm badassery as the combined Stein and Jax convert a Dominator mega-weapon into water as Firestorm finally realizes his true power potential.

4. Catharsis

Yes, the episode ends with the heroes taking the fight back to the Dominators, but the real catharsis comes when Cisco is forced to walk a mile in Barry Allen’s shoes. Cisco, Steel, Vixen and Rory travel back to the 50s and rescue a Dominator from government custody in order to discover the reasons why the Dominators have invaded. Cisco inadvertently allows the Dominator to escape which changes history. Cisco has the best of intentions — he wants to save his world — but he still changes the timeline. Just like Barry. Now, Cisco is able to forgive Barry, which is exactly what Flash needs to hear as he is ready to surrender himself to the Dominators to end the invasion.

You see, the Dominators believe that beings like the Flash are too powerful to be allowed to exist, so they demand Barry Allen or else they will destroy humanity. Cisco forgives, and the heroes fight back as we are treated to the biggest supe hero throw-down in live-action superhero history.

5. Action Comics

During this fight, everyone has his or her moment, no one is left out as the Dominators are routed thanks to the combined might of the heroes of two worlds. Supergirl gets a portable Vibe gate so you know that this won’t be her last visit to Oliver and Barry’s world. Heroes rise, aliens fall, and Legends stand tall.

This crossover and this finale truly set the standard for future, live-action superhero TV. Both Marvel’s future Avengers films and DC’s future Justice League films will have a hard time reaching the heights of this four-part event that makes me so proud to be a superhero fan. Hall of Justice, indeed.