Leo has come to face the truth about his past when two ghosts want to take revenge on him for leaving them behind in the war.
In my opinion, it's a nice episode that is for once not about the sisters but their whitelighter Leo, which is nice since we don't have episodes like that a lot.
Anyhow, Leo seems to be really weakened and doesn't understand why he deserves to be a whitelighter and Piper and Paige try to make him understand that it's because of all the other people he saved when he died all those years ago. They try to make him remember that but it doesn't seem to get through to Leo. But when the teacher is killed, Leo looses his powers or so he believes because his emotions control his powers as well. But when Piper dies, Phoebe tries to get Piper back. Piper turns into a ghost and casts a spell and vanquishes the ghosts as leo runs to Piper and saves her with his healing powers which he retrieves when trying to give CPR to Piper.
Also Cole wants Phoebe to move out of the house and he manages to do so. Seems like everything is going according to Cole/Source's plan.
OVerall a nice episode, sometimes Brian Krause's acting wasn't best but overall it was really good. His acting as was the sister's acting... Enjoyable and definite character development for Leo, now that we know more about his death and how he died. And he's come to realise that he deserves to be a whitelighter