Lucas Randall is a bit of a conspiracy theorist, he suspects that there is something deeply strange about Blake Holsey High long before his best friend and roommate, Marshall Wheeler, or the third member of the school Science Club, Corrine Baxter. Lucas claims to have once seen a woolly mammoth in the school's swimming pool, but the others don't believe him. Of all the members of the Science Club, Lucas is the most driven in his determination to discover the school's secrets. He is an excellent chess player, but not very good (or at least unlucky) at Hearts.
Lucas is the last person to see Professor Middleton before he disappears at midnight, during which Lucas see a strange light shining through Middleton's door. When Josie Trent arrives at Blake Holsey, she quickly comes up with a theory that Middleton disappeared through a vortex or black hole. They soon discover the wormhole in the science office, after which Lucas starts referring to the school as Black Hole High.
Smart and tall but athletically hopeless, Lucas is regularly picked on by Stew Kubiak and other school bullies. At one point, Lucas is impatient to grow up and no longer have to deal with such indignities - and he gets his wish. Lucas temporarily becomes an adult after being bitten by a mayfly, which has an exceedingly short lifespan. This "adult" Lucas, played by Andrew Tarbet of The Famous Jett Jackson, poses as a substitute math professor, hangs out with Principal Amanda Durst, and even berates Victor Pearson for treating Durst badly.
Lucas lacks any confidence in his love life, except during one wormhole-assisted bout of bravery, during which he suavely secures a date with a beautiful new student from Italy, even speaking to her in Italian. However, she is not Lucas's main love interest. Clearly smitten with Josie, Lucas shows considerable jealousy toward Vaughn Pearson, who has an on again, off again relationship with her. This fuels Lucas's suspicion that the younger Pearson is involved in the clandestine activities of his father, Victor Pearson. Nevertheless, Lucas saves Josie and even occasionally Vaughn from disaster. It is Lucas who finds a way to bring Josie back into sync with normal time after her time-slowing watch breaks, and it is Lucas who casts the deciding vote to allow Vaughn to return his mother's pendant to her in the mysterious holographic device from the future.
Most of the time, however, Lucas is highly suspicious of both Vaughn and Victor. Lucas lies about his father's availability in order to stay at Blake Holsey over a school break, so that he can investigate the school, the Pearsons and the wormhole with less interference. During this investigation he finds himself back in Middleton's office, learns of a tesseract device, and sees Middleton's disappearance firsthand. Despite the tesseract incident, Lucas has a good relationship with his own father, and often goes fishing with him when not at school.
After Josie's disappearance, Lucas never gives up on finding her and bringing her home. When Josie's clone allows herself to be trapped in a pocket universe in order to free Josie, Lucas becomes determined to find a way to rescue the clone as well. He eventually decides to become Z's sidekick and stay at Blake Holsey High.
(2002 - Present; Best Friend, Crush)