Wolfram and Hart target Angel - and Faith is the weapon
Angel's meddling in an important court case upsets the lawyers at Wolfram and Hart. In an attempt at revenge, they hire vampire slayer Faith to kill him.
Faith has recently fled from Sunnydale, on the run from the Watcher's Council after a bizarre body-swapping incident with Buffy.
After several failed attempts, Faith kidnaps Wesley and tortures him in an attempt to lure Angel into a trap. After a spectacular fight between vampire and Slayer, Faith breaks down, crying "I'm bad, please just kill me".
Trivia: Eliza Dushku played vampire slayer Faith in season three of Buffy. The character went into a coma and didn't wake up until late in season four. Five by Five directly follows on from events in the Buffy episodes This Year's Girl and Who Are You.