Prue and Piper cast a spell to summon and vanquish Belthazor, but instead the demoniac bounty hunter Krell appear in his place. Krell tells them that Belthazor killed The Triad and The Source ordered Belthazor's death. The sisters associate with Krell to chase and destroy Belthazor with their magic potion. Meanwhile, Phoebe tries to find Cole, and when she meets him, she sees that he is wounded so she asks Leo to heal him. When Prue and Piper disclose that Cole is Belthazor, Phoebe has to decide if she vanquishes or saves him.
"Sleuthing With the Enemy" is another great episode of "Charmed". The impossible love of Phoebe and Cole comes to an end, with Phoebe finding that Cole really loves her and deciding the fate of Cole and consequently Belthazor. Her conflictive situation is the climax of this episode.