It goes like this... Following the Slaver Wars, the Spades were forced to leave their firstborn, Jonathan, with a family of friendly An Phar because someone may have been after them. They settled on the Rim World mining station of Paradise with their two other sons, Willie Jay and the youngest, Virgil, but were killed by unknown hands before they could retrieve him.
     He was raised by the An Phar until his early adulthood, when the colony was wiped out mysteriously. Finding them dead when he returned from a lone excursion, he took to traveling, looking for his real family, becoming a space patrolman in the process. Eventually, he found Paradise and his two brothers.
     By then, having grown up without their parents for most of their lives, the somewhat badly adapted Willie Jay had become a belter mining the family-owned asteroids and Virgil, calling himself "Ace", was a professional gambler and racer not always on the right side of the law. Jonathan's goal thus became to reunite his family and keep his brothers out of trouble.
     When Simone Lorcquet came to the station, she shook things up, and not just with her singing at the Promenade night club. All three brothers found her interesting though it would be Ace who would court her more actively.
     Not that it was all fun and games! Ace had to deal with a rather nasty droid loan shark by the name of Oily Pete, and Jonathan had to contend with the xenophobic Station Security Chief Vaugnharvey. And what of "model" citizen Jeremiah  Dark, a rich merchant from the Slaver Worlds who knew their parents and seemed to be hiding something? It sometimes seemed like their only friends were Station Commander Thorndike, who was a friend of their parents, and young Jesse Waylons, Johnny's dime holo-addicted deputy.
     They were never able to prove that Dark was behind the hijackings of multiple supply ships by criminals in yellow space suits, and when the supplies ran too low, the brothers went (not all voluntarily) to a nearby An Phar colony to trade for some.
     After negotiations, they had the stuff, including documents and a knife with a strange inscription. This clue leads the brothers on a quest to find its owner, an outlaw who may have stolen and hidden a piece of equipment of great value. But before they follow up on it, the colony that helped them now attacks Paradise because they've fallen victim to a disease from something traded to them. The Stationis defended, and in the process, Ace makes friends with one of Oily Pete's men, sympathetic droid Jimmy "Lasers".
     Now following their leads, they fly/jump to the planet Salvation, and then to Rosary, all the while disturbed by dreams of bulls come to revenge themselves on the owners of weapons used to kill the colonists, which turned out to be "micros" smuggled on them to affect their thought patterns. The piece of equipment will be found in a junk yard on Rosary that allows the brothers to at least pay off Ace's debts.
     On this trip they meet Lupita, an explosives smuggler Johnny has to bring to justice, but she gets away (without her merchandise). Willie Jay seems interested in her, but he kinda smells, you know?
     Back home, Ace decides he'll go to the Casper System soon to participate in a race for big money, and then there's another attack on a convoy. Johnny flies out to stop them and he crashes into an asteroid and isn't able to help. Deep questions as to the effects of this first Shift are explored, but no answers come up. Investigations into the convoy hijackings turn up nothing even with the help of Dir-Ro-Hem Ma-Lo Phar, an old An Phar friend of Johnny's. Meanwhile, Willie modifies Ace's ship for the coming race.
     When asked to throw the race by Oily Pete, Ace refuses, but still gets his ass kicked by Lupita who may be cheating. The race will end in a fireball when a ship crashes into a spectator outpost, gravely injuring Simone and killing Dark, though he is cloned quickly enough. The brothers visit Simone in the sickbay and again mystified by a Shift, they try to collect their wits before they are sent on an expedition into the old Slaver Worlds territory to survey for activity by the reptilian Kaa. On the way, they find a clue to the identity of the convoy hijackers - a piece of spacesuit with some writing on it similar to DarkUniversal's logo...? 
     The brothers come across a damaged Kaa outpost that attacks them, and they must neutralize its automated security systems. The ship contains a half-dead alien of unknown origin! They return to their ship with their prisoner, and learn via subspace radio that a neutron weapon has hit the already sick An Phar colony, and destroyed it completely.
     Upon their return to Paradise, the station is attacked by Fang-class fighters, and Dark claims someone has betrayed the station to the Kaa. The brothers volunteer to prove it wasn't them despite their frequent off-world trips.
     They find the true culprits, Kaa holed up at the edge of the Galaxy. They also discover that they are working with Dark and are most probably the hijackers that have made their lives difficult. They beat the bad guys, but also confront Dark, who shows his hand by admitting he killed their parents, as well as hinting that he too, shifts. The confrontation turns violent as Dark squares off against the brothers in his fighter craft. The station is badly damaged in the battle, forcing Vaughnharvey to declare martial law, and then Dark is finally killed as his ship explodes.
     Through this, Paradise gets wind of a secret Kaa operation to kidnap citizens and start their slaving ways again. Investigating, Johnny is kidnapped as well. He's rescued, of course, and Paradise's commander approves an attack on the far side of the planet below, where these Kaa are apparently set up.
     The damage and very public mess of the last few days leads to a trial (of course called by Vaughnharvey) in which Oily Pete tries to frame the brothers. Ace proves him a traitor instead and destroys him during an oily escape. The other fallout from this is that Willie Jay is offered an research position on Braggi II, AKA Cretaceous, to further keep him out of trouble (outside his brothers' influence). He leaves by ship for that untamed world, but leaves his brothers their parents' journal, in which they find mentions of possible shifting on their parts too, as well as examples of a strange language that never changes from shift to shift.
     Attending Oily Pete's funeral (A.I. are afforded them), Ace is challenged to a duel by Pete's factory brother Greasy Gil. It will end badly for Gil, who gets his ear sensor destroyed and disappears in the service ducts of the station. Meanwhile, Ace can't see Simone because her father Horace Lorcquet has arrived to see what kind of decadent life she's leading and doesn't approve.
     Thornedike is later murdered and Vaughnharvey asks the brothers for help in the investigation. They find that he didn't want to do business with dangerous supporters of the nascent Core Worlds Empire, and they had him killed. Johnny and Ace eventually stop a plot by these extremists to destroy Paradise with a neutron bomb, which blows more or less harmlessly outside the system. Greasy Gil returns briefly during this episode, sporting an improved but mismatched ear sensor.
     As Horace Lorcquet is elected Station Commander, putting the brothers' position in jeopardy, they have an Irari linguist, nicknamed Bartleby, investigate the strange script in their parents' journal. He makes headway, but it is stolen by famous explorer Brik Bannon, recently arrived from his 8-year trip around the galaxy. Confronting Bannon, they discover he's a sophisticated android.
     When they bring the computer brain to Bartleby, it gives him they key to the alien alphabet - it's Gerodian! Johnny then has his An Phar contact call her friend, Captain O'Dare of the Hermes, who brings them to the Plato Nebula, which hides the lost Gerodian homeworld. They are all captured there, and the brothers, referred to by the Gerodians as "shifters" are thrown into a different cell... with a man called Twelve.. [Click here for Twelve's history]
     They discover that Twelve is a shifter too, and while they compare notes, Captain O'Dare breaks them out. In getting back to their ship, they discover that the Gerodians seem not only to know about the Shifts, but may be able to control or at least initiate them. They succeed in their escape and hightail it out of there, and when they get back to the Rim Worlds are told by the An Phar that any debt she is owed is wiped clean. Paradise is in mourning, however for the loss of Simone. She's been taken in the night by a Kronin war brgade. Mad with love, Ace goes after her, and with the help of Jonathan and Twelve, reaches the moon where they have set up camp.
     They only want Simone to record a song that will inspire their people to a new motivation, now that slaving has been banned on a galactic level. Their culture has been adrift ever since and needs a periodic "tuning" and cross-polonisation with other peoples (a role that used to be filled by slaves). After a contest of skill won by Ace, an alliance is made with the Kronin thanks to the promise of Simone recording (and producing, with other artists) music periodically for Kronin consumption. Returning home as heroes, Commander Lorcquet warms up to the brothers, and even offers Twelve his own quarters.
     This decision is contested by Vaughnharvey, who mistrusts espers, but it is finally decided upon, though a vision he has of a ship exploding makes the officers of Paradise wary and start to plan their next territorial expansion a little better.
     Given their past involvement with the Kaa, the trio is sent on a mission to prevent them from assassinating VIPs on a giant cruise liner named the Gigantic. They successfully do so and continue to rise in the esteem of Paradise's officers. Young Jessee Waylons even graduate to full security officer. But while Jonathan and Twelve are on a mission with the kid in the Aegypt sector, Ace gets wind that Willie Jay is no longer sending his reports from Cretaceous. He undertakes a rescue mission alone and finds his brother in a tank of amniotic fluid. In the shadows, Jeremiah Dark lurks, alive and well somehow, and he's stolen something from Willie. Some kind of shimmering particles extracted from his body! In pursuit, the two Spades are distracted by a grouchy local animal while Dark escapes.
     Getting back to the ship, they are surprised to find Willy remembers things differently, i.e. he doesn't have memories native to the present reality, and still believes himself a time agent, with all the requisite skills. He hasn't properly shifted with the rest of the world! It also makes it more complicated for the brothers to figure out where Dark discovered the process he put Willie through, because it hasn't translated in his mind. Speaking of a "cyclical time loop" makes Ace twitch to the Cyclades system, and they start pouring over star maps to find a possible planet where Dark might have developed his techniques, in the hopes of curing Willie's shiftlessness. The jump to Skotadi, the old Greek word for Darkness, and while in transit, Willie learns the basics of this era's technology from the computer.
     They soon discover the planet's inhabitants are willing - or at least ambivalent - slaves of Jeremiah Dark, and have not been told slavery has been galactically banned. Following clues, the heroes brave the planet's wilderness and Dark's security robots to get to his secret laboratory. He is not there to get his comeuppance, but the equipment is there to restore Willie Jay to normal, after which the heroes, with the help of a pair of giant Jerils sick of being slaves, overload Dark's complex and free the colony. After the party, they return to their ship, then home.
Recently... While neither Jonathan nor Twelve have returned, it's a happy reunion between Ace and Simone as things heat up between them. Even her father seems happier with the match (though Ace's cockiness makes that difficult later on). Things get complicated when Twelve's long-lost biological mother shows up on the station, but before she can tell her story, she's attacked by an artificial intelligence and placed in a coma. With the brothers suspected of the crime and the murder of a prominent scientist, they are given 48 hours to clear their name and, as it turns out, stop the A.I. before it turns everyone into a droid using a nanovirus. Simone is almost converted before it's too late, and the boys walk away from the adventure with a stronger friendship with the Konin ambassador (whose people see A.I. as abominations), a new one with the station's underground fixer Bellune, and quite the opposite with a dumb criminal called Helm. When Twelve's mother wakes up, she tells the Spades she used to work with their parents and came in late the day of the accident that turned them and Dark into shifters. After a year of working on the data as technicians disappeared left and right, Mary and Richard Spade suspecting foul play by Dark (who was pushing to control reality rather than fix what was broken), jumped their lab-station into hyperspace and made everyone take escape pods and scatter to the four winds. Twelve's mother, discovering she was pregnant with Dark's child, dropped him anonymously at an orphanage while she hid under different assumed names lest Dark track her down. Only now does she feel safe to come looking for her son as she's (incorrectly) learned Dark was dead. She gives the boys the coordinates of the lab, probably still floating where it came out of hyperspace, at a location unknown to Dark.
     When Ace and Willie try to access it, it releases drones they must fight and jumps into hyperspace. Close-by Fasanni know where it is and offer them a deal: recover a relic in Ugor's holy junkyard and they'll get the information. To sweeten the deal, they lend them one of their own as a guide, and give them a cooking droid who turns out to be instrumental in passing the Ugor's rigorous trading ceremony to gain access to the saintly junkyard. They fly to the planet at the center of system filled with ship wrecks and other trash where their guide Splif takes them to a giant crashed ship surrounded by Ugor paladins. With some difficulty, they take possession of the semi-portable graviton that holds the system together. As everything starts to spin out of control, and with Lupita's pirates after them, the boys use the graviton to fly safely out of the trash vortex. The Fasanni make good on their promise and reveal the location of their parents' lab in hyperspace, and once again using the graviton, they punch it out into real space. There, they discover the truth of what they call shifting and set to destroying the large graviton at the center of the station, just as their parents had prescribed. Then in comes Lupita to give them a head's up that she and her crew have stolen the graviton aboard their ship and are bringing it back to Dark, who has paid them handsomely for it and has rebuilt his lab on the planet under Paradise. As the central graviton threatens to blow, they all race back to the docking ring only to find that Lupita's men have betrayed her, scuttled the Trefle, and flown away, leaving her to die with Ace and Willy. The graviton blows and SHIFT>
Shiftworld and all materials pertaining TM Michel M. Albert. GURPS TM Steve Jackson Games.