During a fight against Eggman, Knuckles suffers amnesia. His friends try to help, reminding him of his worst blunders via flashbacks. But he becomes more depressed when he learns that he is the last of his kind - the final echidna. Feeling all alone in the world, Knuckles sets out to find a foster family among the Villagers who might be willing to take him in.
- Ball Bot
- Child Monkey
- Comedy Chimp
- Dave the Intern
- Doctor Eggman
- Fennec Male
- Lady Goat
- Lady Walrus
- Mrs. Dave's Mom Template:Mention
- Mrs. Vandersnout
- Old Monkey
- Professor Cluckins
- Rabbit Girl
- Team Sonic
- Walrus Baby
- Walrus Child
- Warthog Male
- Sonic Boom World
It is another day on Seaside Island, and Team Sonic is engaged in one of their usual battles against Doctor Eggman and his robots. Though the Badnik and Ball Bots keep coming, Team Sonic is easily able to handle them. Amidst the fight, Knuckles the Echidna asks Sonic the Hedgehog for a lift. In response, Sonic activates his Enerbeam, which Knuckles grabs. Sonic then swings Knuckles around before releasing him, sending him flying through a trio of Motobug. Knuckles takes his time to gloat while flying, but fails to see where he is heading and ends up hitting a boulder head-first, which knocks him out. Noticing Knuckles' accident, Sonic takes Amy Rose's advice to wrap this fight up quick so they can tend to Knuckles by taking out the remaining Badniks. Having lost, Eggman retreats in his Eggmobile while saying that he will use his newfound spare time to use some coupons he has at the new falafel place. Team Sonic then run to Knuckles as he babbles in his unconscious state.
Back in Sonic's Shack, a bandaged Knuckles wakes up to find himself surrounded by his worried friends. As Amy answers Knuckles' question as to where he is though, Knuckles reveals that he does not know who Sonic is. This makes Miles "Tails" Prower suspect that the bump to the head Knuckles got gave him amnesia. Denying Sonic's remarks about how cliché this situation is, Tails suggests they try refreshing Knuckles' memory by taking him to familiar places. The team thus takes Knuckles to his weightlifting gear on the beach, where Amy tells Knuckles his name, Angel Island, and the fact that he is the last of his kind. Sticks the Badger then tells Knuckles about his strength and his penchant for lifting things, making Tails suggest that he should try lifting his barbell. Knuckles does so, but still does not remember anything. It is then that Sticks scares Knuckles, making him drop his barbell on his head. Sonic asks Sticks why she did that, to which she replies that scaring someone is the best cure for amnesia. Amy corrects her, saying that is for hiccups, but Sticks is not worried.
As Knuckles comes to, Sonic tests out his well-being by asking him how many fingers he is holding up, to which Knuckles remembers his inability to count. To confirm his recovery, Amy has Knuckles tell them things about himself. As Knuckles goes over everything he knows about himself, though, he gets depressed as he recalls that he is the last of his kind. Tails wonders why this is bothering Knuckles since he has always known he was the last of his kind, to which Knuckles replies that his head trauma has made him think clearly for the first time ever. Not wanting to be alone, Knuckles resolves to find a foster family.
Going to the Village Center, Knuckles visits several houses to offer himself as a foster child to the residents. However, he gets turned down repeatedly, making him more and more desperate. As he is about to give up though, Knuckles visits Mrs. Vandersnout, who agrees to take him in since she needs a houseboy to take of things around her house. Deeming this acceptable, Knuckles joins Mrs. Vandersnout in her house. Inside, Mrs. Vandersnout tells Knuckles about her late husband when he notices his photo. However, she tells him not to sit on her visitor-exclusive furniture and quickly gets annoyed over Knuckles' "sassy" attitude. Mrs. Vandersnout later has Knuckles take her to Meh Burger (location) at 4:00 PM for the "Early Bird's Special", where they meet Knuckles' friends. While Knuckles is happy to have Mrs. Vandersnout as his grandmother, his team is unnerved by her antisocial opinions. Mrs. Vandersnout then tries to head home so they can get to bed early, but Knuckles feels she is embarrassing him. In response, Mrs. Vandersnout decides that if he is not going to follow her rules, she will get a new houseboy, prompting her to snatch Dave the Intern from his workplace. Knuckles tries to reflect on the good times they had together, but realizes they had none.
Not giving up on finding a family, Knuckles goes to Gogoba Village to join the guilt-tripping Gogobas tribe. The Gogoba Chief initially welcomes Knuckles, but when Knuckles offers his assistance to a Gogoba who needs help removing a boulder from the village well, the Chief proclaims that Knuckles can never be one of them as his friendly and helpful demeanor is an insult to their guilt-mongering culture. Before Knuckles can leave, though, the Chief guilt trips him into removing the boulder anyway. Back at the beach, Knuckles finds Lady Walrus with her Walrus Child Walrus Baby, and requests to join her family. Lady Walrus agrees, but only if Knuckles tries to be the daughter she always wanted. Knuckles thus joins Lady Walrus and her family at Meh Burger, dressed up as a girl. Watching nearby, Team Sonic finds Knuckles' attempt heart-breaking. Eventually, Knuckles ends up fighting with the Walrus Child over a Meh meal toy. This prompts Lady Walrus to withdraw Knuckles' inclusion into her family, as he has failed to exhibit proper lady-like behavior. Despite Knuckles' attempt to regain her favor, Lady Walrus leaves with her family.
As night falls, a depressed Knuckles sits alone in the Village Center at night, during which Charlie and Belinda come across him. As Charlie confronts Knuckles, the echidna fails to recognize him, prompting an angry Charlie to remind him of Counter Productive. Remembering Charlie now, Knuckles notes how he can relate to that since he cannot find a foster family. It is then that Belinda offers Knuckles to be a part of her and Charlie's family. Behind Knuckles' back, a confused Charlie asks Belinda why she is giving a "demon" like Knuckles that offer. Belinda then reveals that she has the ultimate plan for revenge against Knuckles; by welcoming him into their family, they can prey upon his vulnerabilities and turn him to the side of evil. As Charlie and Belinda laugh in agreement, Knuckles joins them, blissfully unaware of their evil plot. An old-fashioned montage then plays, showing Knuckles engaging in various family activities with Charlie and Belinda, like flying with kites, watching films, having barbecues, and playing Fuzzy Puppies.
Twenty-two and a half hours later, Sonic catches up to Knuckles as he is picking up dinner from the new falafel place for Charlie and Belinda. When Sonic learns that Charlie and Belinda are Knuckles' new foster family, he tries to remind Knuckles that they are villains trying to destroy him. Knuckles, however, thinks Sonic is only besmirching his foster family and runs home crying. Telling Belinda and Charlie about what Sonic said, the pair decides to put their plan into motion. As they admit to Knuckles that they are villains, Belinda reminds him about how they took him in, and if he wants to remain in their family, he has to become a villain too. Though silent, Knuckles agrees to the demand.
Later on, as Sonic, Tails, Sticks and Amy return from the new falafel place (and Sonic complains about the poor state of the food), they are attacked by Charlie in Charlie's Mech Suit and Knuckles, the latter who informs his friends that he is just helping his family. Following Belinda's instructions, Knuckles attacks his friends with a series of Ground pound (Knuckles' move) which Team Sonic barely dodges. As Charlie then attacks with his mech suit, Sticks manages to trap him in her net until Knuckles blows his friends away and gets Charlie back up. Sonic goes in for a Spin attack at Charlie, but has to move away when Knuckles bars his path, unwilling to hurt Knuckles. Belinda thus has Charlie use Knuckles as a human shield while he attacks the heroes. As Knuckles tells Charlie that he is treating him roughly despite having faith in his "unconditional love", Charlie blurts out in frustration that they are not family and that he is being used. Sufficiently convinced he is on the wrong side, Knuckles shoulder flips Charlie’s mech suit to the ground so his friends can land the finishing blows. Realizing their plan has failed, Charlie and Belinda retreat from the scene.
With Knuckles back on the side of good, Sonic tells him it is good to have him back on Team Sonic. Knuckles apologizes for his mess-ups and reveals that this experience has taught him who his real family is, although he struggles to remember his answer. Helping him along, Amy tells Knuckles that she and their friends are his family, and Team Sonic shares a tender group hug. Watching from nearby, the Old Monkey monologues about how he wished that he had a family like that and how he wants to care for someone who comes to him looking for a family. Realizing the futility of that, the Old Monkey takes his leave while, in the background, Mrs. Vandersnout has Dave drag her around, continuing to use him as her houseboy.