One night in the forest, a teen-aged couple kissing in the back of a pick-up truck sees a flash of light.

Liz surprises her father by putting the ring in her nose. After the shock wears off, Mr. Parker invites Liz on the annual Father's Camping Weekend.

The UFOlogist rushes in, looking for Max and further confusing Mr. Parker when he remarks that Liz is Max's girlfriend.

Maria struts into school wearing an "Aqua-bra," which she tells Liz has "all the fun of implants, except without the invasive surgery part." The boys in the hall are very impressed.

Across the hall, Liz notices Max heading into the Eraser Room. She wonders aloud whom he could be seeing there, and Maria cautions her not to pine.

Isabel joins Max and Michael in the Eraser Room, and Max tells the other two what he has learned from the UFOlogist.

He has also learned that Valenti has closed off a section of the woods. Max suggests that they get there first, using the school camping trip as a cover for their presence.

Michael claims he's "off the hook" due to having no father, but he doesn't look at all pleased about it.

Mr. Parker wanders into Liz's room to talk with her about the camping trip. He is embarrassed when she comes out of her bathroom without a shirt.

He then renews his offer to go camping with Liz. She agrees, saying she wants to spend more time with him as well.

In the trailer park, Michael and his foster father yell at each other as he goes outside with a dinner of cereal. River Dog appears, telling Michael "It was real."

Michael figures out that he means the sighting and asks how he knows. River Dog replies, "I've seen it before."

At the Crashdown Cafe, Liz begs Maria to accompany her on the camping trip -- she's afraid of too much family time, especially since her father has become increasingly nosy. After a heated negotiation, Maria agrees to go for $62.50 and a week's worth of math homework.

As Liz gives Maria the money, Maria gives Liz a bag of echinacea for her cold. Mr. Parker sees the exchange, to his dismay.

Valenti arrives, upset that a hiker has gone to the media with the story. He's determined to beat the FBI to the sighting.

Kyle is there to help select a new tent for the trip. He's looking forward to "the only two days in a row" he and his dad spend together, but Sheriff Valenti thinks he's too busy to go on the trip after all.

At the Crashdown, Michael tells Max and Isabel about what he saw, and suggests River Dog is the mysterious fourth alien and their father. Isabel is doubtful, but Michael snaps that this may be because she has a father already.

Across the room, Alex asks Liz and Maria if Isabel is watching him. She isn't. He gets paranoid, suspecting that the whole date thing is a set-up, and runs off to the bathroom to calm down.

As Michael and Max approach the register, Maria spins an elaborate story about going on dates with college men this weekend. Max looks hurt.

Returning from the bathroom, Alex approaches Isabel. She tells him that that she won't be around this weekend because her father demanded they go camping, and Alex immediately claims he was about to tell her the same thing.

Everyone gathers in the school parking lot, where the bus is being loaded. Alex's father -- every bit as geekish as his son -- asks if camping is such a good idea.

Across the lot, Mr. Parker tells Liz and Maria he is glad they will have a chance to talk about important things. Seeing Max, Isabel and Mr. Evans on the lot, Liz and Maria run away to hide, leaving Mr. Parker shaking his head.

Sheriff Valenti joins Kyle, who's surprised and a bit suspicious. Valenti claims he's had a change of heart, but when he sees Max he calls in on his cell phone to ask for more men on the perimeter of the woods.

Boarding the bus, Max sees Liz and asks about her "date." Maria proclaims a change in plans.

Out in Frazer Woods, Max looks for a campsite near the trees. Isabel expresses concern at Valenti's presence.

Kyle picks a site for the Valenti tent, but the sheriff claims his cell phone reception is poor and picks a spot near Max. Alex directs his father to a site near Isabel, while Valenti brings the whole gang together by inviting Mr. Parker to join them.

While roasting marshmallows, Kyle tells Liz and Maria a story about cattle mutilators that he learned from his grandfather. Sheriff Valenti is surprised that Kyle knows the story.

Across the clearing, Max plays poker with his father, Mr. Parker and Mr. Whitman. After Mr. Parker jokingly asks Max what he's hiding, Max surrepititiously turns his full house into a less notable two pair.

As Isabel and Alex stargaze, he gushes at how much he's enjoying her company, and proposes another date next week. She tenses, telling him, "It can't be a date, Alex. It can't be anything like that."

Later, Max and Liz meet brushing their teeth and argue over whether they've slowed down or "screeched to a halt." Liz tells him that she wants to be let into his life and to help find the sighting.

Back in town, River Dog opens the door to Michael's trailer. "It's time," River Dog says.

In their tent, Liz finds her father going through her stuff. He's found the echinacea pills, which she tells him are for her cold.

Mr. Parker is defensive -- he tells her he can't understand her, that "you're so grown-up all the sudden." Liz insists on her privacy.

In another tent, Sheriff Valenti turns off the light. Kyle watches his father.

Outside her own tent, Liz watches for Isabel and Max. When they leave their tent, she follows.

In the woods, Max and Isabel surprise Liz. Isabel thinks bringing Liz along is a bad idea.

Maria joins them, hoping she is breaking up "a woodsy tryst," but deciding to come along on the search. None of the teens realize that Sheriff Valenti is following them.

Maria complains about the cold, commenting that her Aqua-bra has become "an ice bra." The group hears search dogs in the distance, and they run.

Mr. Parker invites Liz into the tent, and is concerned to find her gone.

Liz offers to stay behind with Maria so the dogs will have someone to catch. Max and Isabel leave, while Liz and Maria wait.

Elsewhere in the woods, Michael and River Dog hike to the site. Climbing over a fallen tree, River Dog twists his ankle. Michael invites him to heal it himself.

River Dog denies the claim that he's Michael's father. He is not alien, even if he does know a few things.

Michael heals River Dog's leg and has a vision. He sees images of River Dog standing, of himself outside with alien symbols all around him, and a hand reaching out.

Back with the police searchers, Mr. Parker is happy to see Maria and Liz safe. Mr. Evans is still looking for his children.

A police officer comes into the clearing with the UFOlogist, who was out searching with a metal detector. He says that they are all in danger.

Sheriff Valenti continues to follow Max and Isabel. He is stopped by Kyle, who confronts his father, saying he wanted to see what was more important than him.

In the clearing, Max and Isabel join Michael and River Dog.

Sheriff Valenti warns his son to clear out. Kyle tells his father that he now understands what it is like to be seen as a low priority -- just as his grandfather treated the sheriff -- and leaves.

In the clearing, the aliens find a spiral symbol matching one they saw in the caves. It glows under their hands, and Michael says the symbol means that the fourth alien is back.

Sheriff Valenti enters the clearing, and Michael and River Dog block him long enough for Max to erase the symbol. Valenti sees nothing.

Max thanks him for finding them -- they had wandered away and become lost. The aliens and River Dog walk away, leaving a dispirited Valenti alone in the clearing.

Later, Sheriff Valenti stares into a room of elderly people at a care facility. An orderly points out the Sheriff's father.

James Valenti, Sr. has trouble putting his pears onto a spoon. "Damn pears," he says, to no one in particular. "Slippery."

Sheriff Valenti approaches, announcing himself as "Jimmy." He comments on how long it has been.

After a tense moment, Valenti sits and tells his father, "Maybe you were right. Maybe you were right all along. And I'm sorry."

He offers to help his father. The elder Valenti stares for a moment, hostile perhaps, and then accepts. Sheriff Valenti spoon-feeds his father pears.