Beta Testers is a prequel novella in the Big Sigma setting. It’s important to use the right tool for the job… even if that tool hasn’t been tested. Garotte is the sort of covert operative a military sends in to tug at threads until a situation unravels. After a particularly ill-advised assignment causes the situation to escalate, he takes it upon himself to right what’s gone wrong before it gets out of control. The task is too big for one soldier, so he seeks out the aide of Jessica “Silo” Winters, a more traditional soldier with whom he shares a complex past. But a battle can’t be fought without weapons, and beggars can’t be choosers. Fortunately, Garotte has the name and address of an ex-military contractor, a man called Karter Dee. Unfortunately, Karter’s equipment isn’t always as reliable—or sane—as one would like.

In a distant future, Trevor "Lex" Alexander was shaping up to be the next great race pilot until a fixed race got him banned from the sport. Reduced to making freelance deliveries, he thinks his life can't get any worse. That's when a package manages to get him mixed up with mobsters, a megacorp, and a mad scientist. Now his life depends on learning what their plans are, and how he can stop them.

Following his last adventure, Trevor "Lex" Alexander's life has managed to return to normal. He's back to splitting his time between delivering packages and transporting passengers, along with the occasional foray into testing highly experimental equipment. He's even gotten back together with his girlfriend Michella Modane, who has been launched to stardom by her coverage of the Bypass Gemini incident. Yes, things are going quite well for Lex. But in his life, luck like this never lasts long. Sure enough, while he is preparing for a rare visit from Michella, he receives word that the reclusive inventor Karter Dee has been kidnapped. The eccentric and slightly deranged inventor's checkered past has made getting the authorities involved out of the question. That has left "Ma", the AI in charge of cooking his meals and reining in his insanity, with few options. She has reached out to Lex as one of the few people she can trust, and needs him to help assemble a team of Karter's former allies to take him back before his latest contraptions can be put to work terrorizing the populace at the hands of his captors.

Artificial Evolution is the third book in the Big Sigma series, building upon the story and characters introduced by Bypass Gemini and Unstable Prototypes. Lex, Michella and Squee are once again joined by the mercenaries Silo and Garotte. Along the way they'll need plenty of help from mad engineer Karter Dee and his AI Ma. After butting heads with the megacorporation known as VectorCorp it was only a matter of time before Lex Alexander and his girlfriend Michella Modane would face the consequences. It is remarkable what a single corporate agent with the resources of a multi-global conglomerate can do to a person's career. In the space of a few days Lex is looking for work and Michella is feeling pressure from the network to ease off the hard-hitting stories. Not one to be silenced, Michella quickly hatches a plan to continue her investigations under the guise of a fluff story about a so-called extraterrestrial, and who better to be her personal driver than Lex? Meanwhile, mercenaries Silo and Garotte are still nipping at the heels of the terrorist group known as the Neo-Luddites. Rumors of an attempt to secure a devastating weapon bring the pair to a forgotten little planet in an undeveloped corner of the galaxy. Circumstances require that local authorities lay claim to the terrorists' apparent target, but what sort of threat could one gangly collection of anatomical curiosities pose to the galaxy? The answer to that question will put our heroes to the test and leave a whole world hanging in the balance.

Temporal Contingency is the fourth book in the Big Sigma Series. Trevor “Lex” Alexander’s life has been less than blessed. In the past year he’s had to battle corrupt corporations, deranged techno-terrorists, and a robotic scourge. Now he’s received the opportunity to finally return to the racing career that had been cut short by some poor decisions. One could excuse him for not wanting to be embroiled in another insane adventure when he is so close to returning to his life’s calling. Sometimes the call of duty will not be denied. Karter Dee, a certified lunatic responsible for many of Lex’s recent woes, has discovered a threat on an unprecedented scale. He and Ma, his AI caretaker, know their plan to solve the problem will take a special mixture of competence, improvisation, and disregard for personal safety. Reluctance aside, Lex is the only man for the job. Even with the skilled pilot on the team, the scope of the problem has grown so massive that it may be unsolvable in its current state. Some would consider the situation hopeless, but any good engineer knows if you can’t find a solution, you have to change the problem. To give human society a chance at a future, Lex, Karter, and Ma, will have to venture into the past.

What would you risk to do what you were born to do? Since college, Lex Alexander has had two loves. Hoversled racing, and Michella Modane. Everything from mega-corporations to robot rampages have threatened to keep them apart. Now, at long last, Lex may finally get a chance to race again. Just one thing stands in his way: Michella herself. The people behind the league have a history in organized crime. Lex believes they’ve gone legit. Michella isn’t buying it. He’s desperate to get back on the track. She’s determined to find what the league is hiding. This second chance may be their last.

When you’ve lived a life like his, the last thing you want is for history to repeat itself. Lex has teamed up with mad engineers, clashed with technology-obsessed terrorists, and faced murderous robot hordes. He’s even traveled through time. He has skills no one in history has ever had. He’ll need them. Devastating cyber-attacks are targeting him. His closest allies are nowhere to be found. Ominous threats from his past seem to be leaking back onto his life. With the help of an off-kilter ship AI and his ex, Lex will have to get to the bottom of it all. If he doesn’t, the galaxy’s days are numbered. Nova Igniter is the sixth novel in the action-packed Big Sigma series by Joseph R. Lallo.