The protagonist, Lugubrious Mote, is a female, sentient mole-flea who lives on the hair of Salacious B. Crumb. Mote and Crumb have established a mutually beneficial arrangement in which they share the scraps that Jabba Desilijic Tiure tosses their way. This changes the day that Luke Skywalker shows up.
Mote is present when R2-D2 and C-3PO played a hologram by Skywalker offering to seek an audience with Jabba to bargain for the life of Han Solo. Mote thinks that Skywalker is foolhardy and a con artist. From Mote's point of view, nothing happened until Leia Organa's failed attempt to rescue Solo.
Mote is present when Leia is captured with Solo and forced to wear a dancing-girl costume. Mote thinks that Leia is a courageous woman for attempting to infiltrate Jabba's palace to rescue his most prized possession from under his nose. Despite Leia's humiliation, Mote admires her steely resolve and determination to remain calm.
Jumping into Leia's ear, Mote makes contact with Leia. She counsels that the human was mistaken to see Jabba as an equal and to think that she could sneak into Jabba's Palace since Jabba is a "great thief." Leia agrees with Mote's points but asks the protagonist to show herself. Mote reveals that she is a mole-flea. While resting on Leia's finger, she listens as Leia narrates the story of the Death Star, the Rebel Alliance, and their vision of a free galaxy. Leia promises that there will be a seat for everyone in the Senate chamber regardless of their wealth, power, language or size.
When Mote asks if it is possible for mote fleas like her to spread across the galaxy and advise generals, senators, moguls and opera singers, Leia says that is possible since her species is smart. When Mote asks if she could advise Leia, the human admits she is uncomfortable about having a flea living on her but suggests Chewbacca as a possible host. Mote agrees to assist Leia in her escape in return. Leia says her friend Luke is coming to aid her.
Luke forces his way into Jabba's palace and uses a Jedi mind trick to compel Bib Fortuna to awaken Jabba from his sleep. Watching the confrontation, Mote is curious about the powers of the Jedi of old. Skywalker demands that Jabba release Solo and Chewbacca to him. Mote tries to communicate with Leia, but she initially can't understand the flea. Adjusting her tone, Mote tells her that Skywalker knows only one trick and thinks that is enough. She warns Leia that Luke is making the same mistake Leia made. She remarks that Jabba makes a living devouring forgers, con men, and liars.
Leia disagrees and Luke continues his ultimatum to Jabba , offering Jabba an arrangement. Leia thinks that Luke's plan is working but Mote warns that Jabba is reeling him in. C-3PO tries to warn Luke he is stepping on the trapdoor but it is too late. Jabba releases the trap door. At the same time, Skywalker grabs the Gamorrean guard Jubnuk's blaster, and the two fall down the trapdoor. Upholding her promise to Leia, Mote leaps into the trapdoor and lands on Luke.
Mote is present when the rancor Pateesa is unleashed on Luke and Jubnuk. Pateesa devours Jubnuk before turning to Luke. Mote encourages Luke, who believes that she is the Force ghost of his late Jedi Master Obi-Wan Kenobi. Mote realizes that she has to pretend to be Kenobi in order to save Luke. While moving through Luke's scalp, she tells Luke to reach out with all his senses and to let the Force guide him. Believing that the Force is tickling his scalp, Skywalker fends himself with a bone.
At Mote's advice, Skywalker jams the rancor's mouth with a long bone. This causes Pateesa to release his grip on Skywalker. Mote directs Skywalker to a door at the end of the rancor's den. However, he finds the door barred by a metal grill. The guards drive him back. With Skywalker cornered, Mote counsels Luke to show him what he can do to take the rancor down. When Luke decides to use the Force, Mote thinks that Skywalker is not very smart but is determined and trusting.
Mote convinces Skywalker to throw a rock at the remote controlling the door, causing the gate to crash down on the rancor's head, killing him. Mote and Leia are amazed that Skywalker defeated the rancor while Jabba and his minions are horrified. As Skywalker is led away, Mote remarks that Skywalker has an endless supply of hope.
At the Great Pit of Carkoon, Mote is present when C-3PO under duress tells Luke, Han and Chewbacca that Jabba will offer them mercy if they beg for it. Skywalker warns Jabba this is his last chance. He demands that Jabba free them or die. Jabba orders that the execution begin. A disguised Lando Calrissian nods to Skywalker.
When Skywalker remarks that the Force is with him, Mote tells him to do what his tingling scalp tells him. Skywalker signals to R2-D2 before jumping over the plank. R2-D2 fires Luke Skywalker's green lightsaber, and Luke fights the skiff guards. Leia strangles Jabba with her chain. Solo causes Boba Fett to crash into the Pit of Carkoon, where he is dragged down by the sarlacc. Luke and Leia escape the blazing Khetanna and reunite with Solo, Chewbacca, and Lando.
While departing, Mote talks with Leia, telling her that she was right that Skywalker did grow on her. Leia says that she told her so. Mote asks to not be mentioned to Skywalker. She recalls that the kid was so joyous about having used the Force to save his friends that she did not have the heart to tell him the truth. While Mote says she does not mind getting the credit for helping Luke, she does not want to discourage Skywalker since the latter has given her hope. After bidding Leia farewell, Mote goes to join a circus.
While reflecting on her adventures with Luke and Leia, Mote wonders what happened to Luke after the events on Tatooine. She hopes that Skywalker has learned to think for himself instead of just trusting voices in his head.