The girls are at P3 venting their worries: Piper about impressing a future nanny applicant, Phoebe about Cole's impending return, and Paige about her lack of love life. Appropriately, Cole is in a dive bar in the process of being robbed. Content to let the robbery continue, Cole changes his mind when his drinking glass gets shot to pieces. Not one to take such things sitting down, Cole proceeds to stand up and slam the thugs into the wall with a wave of his hand. As the panicked patrons flee, Cole crosses the line by incinerating both thugs in less time than it takes to say it. In agony over his actions and his hopelessness, Cole cries out... and is heard by two mysterious gentleman who claim they've been waiting for the right moment with him.
The next morning, Piper is fervently preparing for the nanny applicants when Leo orbs in to tell Paige that she is going to be given her first whitelighter charge. In Leo's words, a "lost soul" in need of help. Phoebe comes downstairs rallying the team as she tells them that Cole likely killed two human beings the previous night.
Back at his penthouse, Cole returns to find the two gentleman waiting for him. Believing them to be evil, he says he won't join them. The gentleman introduce themselves as representatives of the Avatars and claim to be beyond good and evil; simply a collective of power content to use whatever means necessary to accomplish their goal. They explain they want Cole to join them and it is inevitable. Cole is in no mood and tries to blast them both... but to no effect.
They depart and Phoebe enters to a very pissed Cole. Not to be outdone by his annoyance, Phoebe threatens that if Cole harms anyone, she and her sisters will vanquish him. Surprised at the possibility that they could have the power to vanquish him, Cole taunts Phoeve only to be dared to try her. Which actually strikes him as an excellent idea.
Paige goes with Leo to meet her "lost soul" and is disappointed to learn he is a drunken former whitelighter. Leo leaves Paige to try and connect with her new charge while Piper begins the interview process. A nanny elf applies and quickly takes charge of the interview for herself when she questions Leo and Piper about who is responsible for protecting the baby from evil attacks. Right on cue, Paige orbs in with her charge who is being hunted by a darklighter. This darklighter is a bit stronger than normal as Piper's explosion power only maims him, but doesn't vanquish him. He retreats only to be found by Cole who drafts him into a plan to force a showdown with the Charmed Ones. Cole heals the damage Piper inflicted and gifts the darklighter with new powers enabling him to stand up to the Charmed Ones.
Back at the Manor, Piper and Phoebe recognize Paige's new charge as being Paige's father and their mother's loving whitelighter, Sam. Deciding to be discreet till they get some answers, Phoebe and Piper concoct an excuse for Paige to investigate the darklighter while they question Sam and Leo.
Sam is reminded of how he was supposed to be in the afterlife with Patty Halliwell, but then says his whitelighter status was restored and he couldn't live with the shame and heartbreak of being forced to part from both his daughter and his love. Piper and Leo can identify with the hardship but still try to convince Sam to give Paige and himself a chance at a family reunion. Unfortunately, Sam is not inclined to listen so he orbs away with Piper and Leo orbing hot on his trail. Shimmering in to confront the Charmed Ones, Cole manages to hear the conversation and decides to include this rift in his plans with the darklighter.
Meanwhile, sensing the vagueness of her sisters, Paige questions Phoebe and learns Sam's true identity as her father. Shocked and annoyed by this news, Paige looks over her shoulder to see Sam has returned and wishes to speak with her alone in the living room. As she discusses her lack of feelings for Sam, Paige is a bit stunned to feel antagonized by this man who abandoned her.
Back in the kitchen, Phoebe congratulates Piper and Leo on bringing Sam back who are stunned when they tell Phoebe Sam did NOT come back with them. All three rush into the living room to warn Paige who is confused until she sees Sam shapeshift into Cole. Not the last surprise of the evening, The darklighter enters and this time, thanks to Cole, he is now immune to Piper's powers and manages to have a crossbow able to shoot at Piper, Leo, and Paige at the same time.
While Piper's baby protects both her, Leo and Paige are both wounded. Content with their damage, Cole and the darklighter depart.
With Cole's plan having been completed, the darklighter locates and prepares to kill Sam but is stopped by Cole. Cole needs Sam to recover and heal Paige and Le so the Charmed Ones can come after him at full strength and vanquish him. The darklighter isn't so easily deterred and so gets vanquished by Cole.
With all the preparation complete, Cole goes to work on setting his affairs in order while waiting for the Charmed Ones. Piper finds Sam and tells him of Paige's need for healing. However, Sam can't let go of his grief and anger so can't access his healing magic. Ever the advisor, Phoebe convinces him to let go for Paige's sake and Sam agrees. Finding his desire to do good again, Sam is able to heal both Paige and Leo. While a bit unsettled by Cole's brazen new attitude, the Charmed Ones get to work on a vanquishing potion to end thie battle with Cole.
At the penthouse, Cole is settling his affairs when he is again courted by the Avatars. Noting what a waste his attempt at suicide is, they choose to leave just before the Charmed Ones arrive.
Phoebe demands Cole stand and face them. He reveals to them that the darklighter was too unruly and so was vanquished so it is just them against him. With everything in place, Cole takes off his wedding ring and stands up ready for his vanquishing. Paige and Piper each throw a potion at him, but the effect won't be complete until Phoebe throws her own as well.
Looking past Cole for a moment, she glances at what Cole was doing before they entered and realized that suicide was the end of his plan all along. It explains the brazen attitude and lack of fight Cole is putting up. Uncomfortable with vanquishing him on his own terms, Cole says she won't help Cole commit suicide. He smirks as he responds that she already has and then uses his powers to get the potion out of her hands and have it throw itself at him. An inferno is ignited with Cole at its center as the whole penthouse is corched from the magickal effect.
When the smoke literally clears, the Charmed Ones are knocked down and Cole is still standing... unvanquishable. Stunned by this turn of events, Cole surmises the Avatars knew he couldn't be killed and he shimmers away leaving a very unnerved Charmed trio in his wake both at his raving and their inability to truly hurt Cole.
The next day, Paige is considerably happier about having met her dad and decides to give an old boyfriend a new chance just as she has gotten one of her own. Phoebe is searching for ways to try and vanquish Cole while Piper and Leo lament the actions of the nanny elf who gossiped all about the lack of safety at Halliwell Manor. As the morning ends, all agree that they'll just have to move on and see how things turn out.