This episode is half good action and acting and half idiocy.
The good is that Leo finally gets to tell Piper he is an Avatar, and that there is a heavy dose of Leo and Piper. There also are many cool vanquishes, including a mass vanquish by Leo that closely resembles the powers Wyatt has.
The idiocy is everything that happens after Brody finds out. Let me state something I'm probably going to repeat- Agent Brody's character, though well-acted, is the worst written, most poorly conceived character in the Charmed universe. This episode is the beginning of his homicidal quest to kill an Avatar, and why? Because they killed his parents. Oh wait, no they didn't. Well, no matter. He heard they were bad. So bad, apparently, that Leo should die just by being an Avatar himself, never mind the fact that Brody would be dead at least once if not for Leo healing him. SO BAD apparently, that Brody would be willing to hold Phoebe at gun point for an opportunity to kill an Avatar.
Somehow the sisters let Brody and his potion into the same house as Leo. Hey, Brody, come on over! Then, with Phoebe held at gunpoint, Leo walks closer and Piper does nothing. Hey, how about just freezing Brody? Or, how about Leo just orbs out of there? Then what was Brody going to do?
Anyway, so Leo fries Brody, but Brody somehow manages to throw the potion far enough to kill Leo. The Avatars appear to lecture Leo about how him telling Piper caused all this? Whuh?? I thought Brody being a crazed maniac caused this. So, Leo rewinds time to before he told Piper. Whuh?? Couldn't he just rewind it to before Brody dropped the potion? Whatever.
To top it all off, Brody is given a free pass at the end, and we have to put up with the guy who just tried to kill Leo and held Phoebe at gunpoint being Paige's boyfriend, which means she'll spend the next so many episodes defending the guy and ignoring her sisters.
Fortunately, this story arc doesn't last long.