The episode begins in Veronica's garden with Finn, Marguerite, and Roxton, seems insects of some sort have destroyed the garden. What do we need? Simple, a food substitute, Challenger is our man. He comes up with a mush of 'stuff' he thinks will work, and down the hatch it goes. Apparently it isn't all that tasty, and has a mean side effect, he starts to feel 'weary' his vision blurs, he sees a shadow of someone, and passes out.

When Challenger awakes an hour later he concedes that obviously this batch didn't work. He then sends Marguerite and Roxton off to find some medical plants/herbs, even though they insist that he stop experimenting after discovering he was unconscious for an hour.

Finn and Challenger have a discussion about why he's trying to create this food substitute, Challenger says basically that a scientists job is to provide a solution for what one day may be a serious problem. The discussion ends with Challenger saying to Finn 'if you understood the principles [of Science], I'm sure you would quite enjoy it,' he says this like he's trying to include her in his work, and would be interested in teaching her. Finn's response is 'she'd rather be a farmer,' Challenger almost sulkingly bows his head and says, 'of course, I understand.'

Out in the jungle Marguerite and Roxton find a plant that Marguerite thinks is one of the ones Challenger wanted. Roxton however claims it's poison ivy, Marguerite of course doesn't listen and picks it, only to find out a few minutes later that Roxton was right. So now they're looking not only for the plants Challenger wanted, but also for a plant to help skin rashes.

Back at the treehouse Challenger has made yet another batch of his test mush, and subsequently fills his belly with it. Everything seems to be going fine, he hasn't passed out yet, but then someone starts talking to him, only problem is no one else is in the treehouse.......
Challenger looks up to see young man standing in the treehouse, Challenger asks who he is, to which the man replies, 'I'm you, when you were young and focussed, without distractions.' The man claims he's here to insure Challenger fulfills his destiny, Challenger begins to think the man is a hallucination.

Meanwhile out in the jungle Marguerite and Roxton continue their search, Roxton sets up their bedding arrangments for the night, while Marguerite observes that he's set both their bedrolls away from one another. 'Keeping us apart I see,' Marguerite says, 'any gentleman would,' Roxton replies, to which Marguerite says 'you're just afraid of catching it, that's all.' 'As a matter of fact, I'm one of the lucky few that's immune to poison ivy,' Roxton claims. Marguerite moves towards him and says, 'well then, how about a little kiss?' Roxton slowly backs up to get away from her, 'i better chop some firewood, it's going to be cold tonight.' 'Very cold, I promise you that,' Marguerite shouts.

While back at the treehouse Challenger tries to continue his studies, only to be constantly interrupted by a young man, who's only trying to 'help,' he claims. The 'hallucination' claims that Challenger doesn't need the others, 'they're constantly interrupting him, stealing his idea's, and distracting him from his purpose.' Soon after Finn arrives back at the treehouse after some crossbow practice in the garden to find Challenger mumbling to himself. When she asks who he's talking to, Challenger replies, 'himself,' and then accuses her of spying on him, just like the rest of them, 'my life's work belongs to me, now get out of here!' he shouts.

Later that night, Challenger finally pulls himself from his lab and comes out the table to find Finn eating, he complements her on the smell of the food she's made, to which Finn exclaims she's not sharing any with him. After asking her what her problem is, and hearing her answer, Challenger claims to not remember yelling at Finn to get out of his lab. Challenger concedes perhaps he had better get some sleep, only to be awaken later that night, by his wife, 'Jessie,' standing in his room. She begins to put a guilt trip on him, claiming he always chose science over her, 'who did I marry, the man, or his work,' she asks. Challenger says he'll never ever do this to her again, and she disappears.

In the morning, out in the jungle, Marguerite and Roxton awake to find themselves next to one another, with Roxton complaining that his chest is itching. 'I thought you didn't want to get too close,' Marguerite asks, 'I must have rolled downhill,' is Roxtons excuse. Marguerite says that she doesn't itch anymore, however, when Roxtons back is turned, she begins to scratch feverishly.

In the treehouse when Challenger awakes he has his morning 'mush,' and starts hearing and seeing the younger version of him again. This time the young Challenger says that Finn had been in there earlier, searching through his lab, and his papers, trying to find anything to steal. Challengers appears to begin believing the hallucination more and more, and asks it 'what can I do?,' 'kill her' the hallucination replies. Challenger first protests, but then grabs a rifle and heads outside, he comes upon Finn, and takes aim at her, but before he can fire, a raptor jumps out at Finn, and she kills it with her crossbow, catching glimpse of Challenger while doing it. 'You've betrayed me Finn,' he shouts, 'how did i do that,' she asks, 'you were sneaking around in my laboratory last night.' Finn replies that he needs to stop drinking his experiment, and she takes aim at him with her crossbow, 'go back to the treehouse,' 'I'll get you, I'll get you all,' Challenger exclaims, and retreats.

Back on the trail, out in the jungle, Roxton's itch still hasn't gone away, after he tried a plant solution that was supposed to work, and he catches Marguerite itching too. Roxton comes up with a solution of his own... mud.

Jessie has come to visit Challenger in the treehouse again, when Challenger tells her his friends are betraying him, and names Finn, Jessie says that Finn loves him like a father, and that Challenger is falling apart. Then young Challenger comes into play, and begins arguing with Jessie, all of this begins driving Challenger mad.

Meanwhile, out in the jungle, Marguerite and Roxton have found a nice little mud hole, and taken a quick dip, but they get out only to discover that someone has run off with their clothes. In the treehouse Jessie, and young Challenger are still arguing with one another, driving Challenger even madder, he fills a canteen with his experiment mush, and runs madly out into the jungle, screaming and shouting, 'you're driving me out of my mind.'

Finn is on her way back to the treehouse when Challenger passes her, screaming and shouting, 'Roxton and Marguerite better get back here soon,' she says to herself. Only to get her wish, Marguerite and Roxton run by her clad in mud and shrubbery, making a b-line for the treehouse shower. Finn follows them and explains the situation to an embarrassed Marguerite and Roxton.

Outside Challenger has found his way to a cave of some sort, and begins over dosing on his experiment. The hallucination Challenger begins choking Jessie, and Challenger seems to be feeling his own air cut off. Finn and Roxton find their way to the cave Challenger is in, and take his limp body back to the treehouse, Finn claims he's dying, back at the treehouse, Marguerite seconds the theory.

'He needs a blood transfusion,' Finn finally says, Marguerite and Roxton have reservations about the idea, 'how do we know what blood type he is?' Roxton asks. 'I'm type O-negative' Finn says, 'a universal donor, it can be given to anyone.'

After giving him the transfusion, and waiting, Challenger finally begins to show signs of health, and wakes up, he sees Marguerites face, then Roxtons, then Finns, and finally, his wife's, 'I'll always love you George, come back to me,' she says, 'I will Jess, I promise,' Challenger replies. 'Jessie, thats his wife's name,' Roxton says, 'she was here,' Challenger says, 'welcome back to reality,' Marguerite replies.

After recouping for a bit, Challenger and Finn discuss his wife, Challenger says he does hope to get back her one day, but he doesn't think she'll wait forever. Marguerite and Roxton come in, drop off the plants Challenger asked for, and then begin to leave, but before they can Challenger says, 'before we all rush off on another days toil, I think we deserve a small break from our labors, don't you?,' 'are you sure you're feeling okay George,' Marguerite asks, 'you don't have some important scientific experiment to finish?' Roxton asks, 'or an invention to invent?' Finn chimes in. 'Yes, but they can wait,' Challenger says, 'you're saying you want to take some time off,' Marguerites asks him, 'yes, that doesn't sound so horrible does it?, spend some time with friends,' he replies. Roxton walks over to him, and feels his forehead for a fever, 'yes, he feels perfectly normal,' he quips, 'perfectly abnormal,' Marguerite laughs.