What a great pilot episode of V. The easiest way to recap it is to run through the characters introduced during it...
Erica Evans is a FBI agent in New York City's counter-terrorism division. She has a son named Tyler, whose father (Erica's husband) recently left. Erica is protective, Tyler is a bit lost. He's in the hospital when the series kicks off, following a fight. He then gets taken by the Visitors as soon as they arrive. Tyler's friend snags the pair tickets on a ship that takes individuals up to the NYC mothership, where Tyler meets an attractive young Visitor.
She recruits him for the Peace Ambassador program, which the Visitors are setting up in various cities as a way for humans to sing their praises on earth to other humans. Tyler fakes his mom's signature and signs up. He's clearly smitten with the concept of these aliens and with this one beauty in particular.
Erica? She's suspicious. She notices that one terrorist cell's activities have spiked since the Visitors arrived. When she and partner Dale check out the scene where satellite photos show these terrorists recently gathered together a lot of C-4, they discover a dead body. On his cell phone, Erica finds a text message that talks about a secret meeting at 10 p.m.
Erica attends it. Dale waits in the car for her. Inside, she meets Father Jack Landry, a priest that isn't sure what to tell his (suddenly huge) congregation about these Visitors. His message ends up being to at least make these life forms earn their trust, as opposed to giving in to blind, ignorant optimism that the Visitors are actually here to help.
The meeting is led by Georgie, who warns those in attendance that the Visitors have been plotting worldwide domination for years. They've hidden themselves among humans long before these motherships arrived. While Erica is skeptical about this, she becomes convinced when Landry produces photos (given to him by a dying congregation member) of individuals purported to be Visitors. The dead man found at the aforementioned terrorist scene is among them. As this information sinks in, those at the meeting are attacked.
A cool, bullet-shooting drone takes out many of them, while violet Visitors do the rest. Erica is able to fight her attacker off, however, as she's stunned to see who it is: Dale. After bludgeoning him in the head, Erica sees robotic-looking scales where bloo and veins should be.
Ryan Nichols also swoops in to the meeting and helps humans fight off the Visitors. Earlier in the episode, we had seen him tell Georgie that he was no longer involved in "that life," and that his soon-to-be fiancee, Valerie, doesn't know about his past. But Ryan apparently changed his mind, and then laid a whopper on Georgie after taking him to safety: Ryan is a Visitor! There are others out there like him, others that have turned on their own, evil kind. Ryan says he'll join the resistance. When he goes home to break it off with Valerie, for her own safety, though, she's discovered the ring and has accepted his (quasi) proposal.
Then, there's Chad Decker. An ambituous reporter, he makes a good impression on Visitor leader Anna. She chooses him for an exclusive interview, but warns him ahead of time not to ask questions that would paint her kind in a negative light. Chad is hesitant, but goes through with the fluff piece. He's later approached by Anna's right-hand man, Marcus, who says Anna wants to use Chad as the Visitors' mouth piece.
Chad doesn't love the idea of speaking glowingly on behalf of a race he clearly doesn't trust, but as Marcus tells him, this will be huge for his career.
At the end of the episode - as the Visitors are gathering Peace Ambassadors and humans are embracing their supposed saviors - Erica sits with Father Landry. They agree that a quiet, intelligent, forceful resistance is needed. After all, as Erica says, the Visitors are lining up the strongest weapon out there: devotion.