Hello, did I tune in to the wrong show? Wait, it's a DVD. Earth, 2004, etc, bloke I've never seen before goes home and eats some pizza, then takes a phone call. from a Xindi-reptilian. Ummmm... time travel?
After the credits, he goes and picks up a hooker, chloroforms her and injects something. Then he takes her to the secret Xindi lab and hooks her up to the equipment and collects his money.
Meanwhile, in the timeframe this series is actually about, Archer's having food when Daniels turns up. Daniels is supremely unhelpful about the Xindi and their current mission. He says there are three Xindi in Detroit, 150 years ago.
OK, where did T'Pol get 21st century stuff? Heh, nice time transition. Archer and T'Pol go Xindi searching in Detroit. They start by stealing a car. Ineptly. It takes them a few tries to find one that isn't guarded by something. Then they drive around scanning. Then they find they need money, so they rob an ATM. Hooray for Star Fleet morals!
Meanwhile, kidnapping bloke kidnaps another person.
Archer and T'Pol locate the Xindi's building, and they scout around until kidnapping bloke turns up and they watch him go in. Oh, the Xindi appear to be collecting one of every blood type. Must be working on a blood control system. Kidnapping bloke is irked cause the Xindi want to pay him for the last three in a lump sum.
Archer and T'Pol follow kidnapping bloke home, but he climbs out the window and they have to give chase until T'Pol nerve pinches him. They interrogate him a bit. when this doesn't help, Archer starts hitting him. T'Pol disses the 21st century. kidnapping bloke is a bit more forthcoming, and Archer volunteers to be the next kidnapping victim.
They wrestle with drivethrough, because the script was five minutes short, then kidnapping bloke trundles Archer into the Xindi lair. While T'Pol shows off her phase pistol to kidnapping bloke, Archer takes a look around and finds the Xindi are trying to synthesize a biological agent. T'Pol suggests destroying their temporal beason so they're trapped there. Oh yeah, that's a great plan. There's a shootout, and two of the Xindi get away with the virus.
Pursuit takes place. T'Pol gets one, but kidnapping guy tries to stab her and she has to stun him. They chase the remaining Xindi who sets about releasing the virus. They have another phaser-fight until Archer gets the drop on the Xindi. Archer manages to grab the virus before it's released, and then they return to Enterprise and show Trip the dead Xindi and stuff they've brought back.
Back in the past, kidnapping bloke is arrested by the police who don't believe his story about lizard people and ray guns. Teh end.
OK, so how did the Xindi get back to 2004? Do they have a time machine? Why do they not go back in time to when humans numbered in the mere thousands and just shoot everyone?