JOSH SMITH’S hormones are raging, and he can’t wait to get intimate with a girl. He also wants to be a famous rock star, and has an amateur band of his own. One evening, he comes home from band practice to learn his rich, eccentric great grandfather, CHARLES EVANS BASTIN, is dead.
When the will is read, Josh inherits one of Charley’s ugly sculptures while his father inherits the rest. Back home, Josh accidentally discovers his sculpture is a CARGAN, a device used for interplanetary travel as a ghostly presence called an ENTITY. He travels to the planet destination of his sculpture and finds it’s a very exotic place.
Another person is also interested in the sculpture collection. MARK WYCHAM and his ghostly partner MANJAHBA, an entity from the planet Ula, are up to no good, but the nature of their plot is not clear at this point.
Josh tries his sculpture again and meets a girl from the planet Brem. ORIANA introduces Josh to the real reason for the planet’s existence (vicarious sexual activity) and helps him learn Giran, the language of entity travel. Josh decides it’s best if his parents are kept in the dark about the true nature of the sculptures and the strange planet named MYTHOS.
Wycham presents Josh’s father, ROGER SMITH, with a scheme to build the Charles Bastin Museum of Modern Art and gains control of the sculptures we now know are Cargans. Roger, however, still thinks they’re just ugly artwork.
Josh adds a female singer, JULIE KIDWELL, to his band. They’re attracted to each other immediately, but she doesn’t want to have sex with him. He talks her into going to Mythos where they can have sex by proxy. With the addition of a sexy female singer, the band becomes a big hit at a local teen club, and begins to make some money.
Meanwhile, Wycham and Manjaba are secretly operating an entity replacement scheme allowing them to place their co-conspirators in important government and business positions on other planets.
Matters become more complicated when the nursing home returns a sculpture Charley was holding when he died. Josh goes to the planet it serves and finds Charley’s entity. Charley tells him the story of the Cargans and expresses his concerns over the devices being in Wycham’s hands. Charley tells Josh about anomalies appearing in entities visiting Earth, but he assures him the authorities will handle the problem. Josh is not so sure and decides to investigate on his own. He discovers some strange gear in Wycham’s warehouse, and encounters some Ulan thugs who chase him out of the place. Josh escapes by going underground but pays the price in pain.
The next day Oriana visits Josh to see the sights of Earth. Josh takes advantage of the visit by escorting her to see what he found, and she confirms his suspicions. Josh reports everything to Charley, but the Grand Council is not convinced anything’s wrong.
Josh and Julie return to Mythos, but Oriana catches them in the act. Josh now has two girls mad at him and must find some way to solve that problem.
Wycham learns Josh is aware the sculptures are Cargans and fears he may cause problems. To assure control of the teen, he gets Roger to visit the warehouse where he keep the Cargans and substitutes an Ulan entity for Roger’s, but the new Roger arouses some suspicion back home.
Josh makes up with Julie, and Oriana apologizes for being nosy. He’s back in business with the girls and the band, but the band’s deal with the teen club is not as good a Josh thinks it is.
Josh consults with Charley on the strange behavior of his father, and Charley and Josh check out the warehouse holding the Cargans. Charley knows what the equipment is and brings the matter before the Grand Council for Entity Travel. Josh testifies about his father’s strange behavior to help convince the Council to act. The Grand Council raids the warehouse, but the Ulans are tipped off.
The raid begins, but the Ulans are busy destroying evidence. The most incriminating evidence consists of the captured entities, and Roger’s is just being fed into the destruction machine when Charley, Josh and the authorities break in. Charley sees Roger’s entity about to be destroyed and jumps into the machine saving Roger’s life but vanishes in the process.
Roger’s entity is reunited with his body, and all is well again. No one notices a small part of Roger’s entity was missing when the restoration occurred. He appears to be his old self, but is he?
Josh and Julie’s romance is back to normal also. The band tricks the teen club manager into paying them a true fee, and Julie has a surprise for Josh after the next performance.