The Truth Is Out There... and It Hurts

When a warlock from the future arrives in town to kill the people involved in developing a vaccine against evil warlocks, Phoebe has to find his next victim before he does. Meanwhile, after Prue casts a truth spell to see how Andy will take her being a witch, she accidentally includes Piper and Phoebe in on it too. They then begin to realize that while being told the truth can be a good thing, though in some cases, it can really hurt feelings as well.