He is a small man with salt-and-pepper hair, and Chinese features.
At the age of eight, Prax's father had transferred from Europa to Ganymede to build a research lab. Ten years later when his family signed a new contract and moved to an asteroid near Neptune, Prax stayed on Ganymede, where he has lived for thirty years. He got a botany internship in hopes of growing marijuana but realized a third of botany students had the same plan.
He was formerly married to Nicola Mulko with whom he had Mei.
For the last eight years Prax's life he has been working the Glycine kenon, a heavily modified, low-resource, soybean.
During the Ganymede incident Prax is in his greenhouse with Dr. Doris Bourne. As the mirrors in orbit begin their decent onto the moon, Doris urges Prax to leave. After Prax grabs one of his soybeans, the two get into the lift as the mirrors and other debris hit the moon and greenhouse. The power shuts off and back on again, then the two make their escape.
Leaving the greenhouse he proceeded to his daughter, Mei's, daycare. He was stopped by soldiers who tell him that all access to the tube station is closed until the fighting has stopped. Having an intimate knowledge of the layout of Ganymede, Prax found a scooter in one of the maintenance sections. He then proceeded to the daycare avoiding soldiers and gunfire. Once he arrived, Miss Carrie, the teacher, tells him that Mei has already been picked up by a doctor and her mother. Knowing that Nicola was living on Ceres and that she couldn't have picked up Mei he realizes his daughter has been kidnapped.
In the week since Mei's disappearance Prax has developed a routine of places to look at people to talk to. He goes to visit Basia Merton the father of a child with Myer's disease for the fifth time. He tells Prax that he and his family are leaving without finding their son Katoa Merton who is also missing. This angers Prax and the get into a fight ending with Basia's daughter stopping her father from beating Prax to death.
Later, Prax contacts a hacker to hack into the station's security feeds to find out who took his daughter in exchange for a small salad. He soon discovered that Dr. Strickland and an unknown woman are the ones who took Mei. He then has hope that Mei is still alive due to Dr. Strickland knowing about her condition. When Prax asks the boy if he can follow them to see where they went on the feeds he raises the price to a chicken. Not having any he goes home. He then compiles a list of all the children in Mei's therapy group remembering sixteen of the twenty children. He then goes to security center and asks about the children and learns that all sixteen of them are missing. It's then that he realizes what poor condition he is in, having not eaten or exercised in days. He then proceeds to the relief center where he finds himself in the middle of a food riot. It is there that he sees a familiar face that he doesn't recognize immediately, the face of Jim Holden.
Prax, Holden, and Naomi Nagata make their way back to the Weeping Somnambulist where Prax tells them his story. While Amos Burton does recon and gathers supplies, Holden forces Prax to eat a meal and take a shower. Amos returns with a can of "chicken food products" which Holden hopes the hacker that Prax hired will take as a token of payment. Then, Holden, Amos, and Prax make their way to the hacker while Naomi monitors them from the ship. They arrive at the hacker's home for the exchange, but the hacker believes they have more chicken and raises the price. Instead, Amos begins to beat the hacker, eventually being called off by Holden when the hacker agrees to help them. The hacker shows them the footage of Mei being taken by her doctor and another woman whom Prax doesn't recognize, but the school's security registered as Mei's mother. The footage follows them up to an old utility storage area (from before the station was finished) that the security feeds do not follow. They pay the hacker and head back to the ship. With Naomi, they discuss a plan: Naomi will will monitor them and take care of any electronic threats, Prax will be there for Mei to recognize and to give any details on her illness that affects the rescue, leaving Holden and Amos to the violence.
As the three of them head through to tunnels to find Mei, they are ambushed by a group of former Pinkwater Security, led by a man named Wendell. Holden is able to talk them down and convince them to assist them in their rescue of Mei in exchange for getting them off Ganymede. The group arrives at the doorway where they lost track of Mei and begin clearing the tunnels. During their search they come across the dead body of Katoa Merton. Filled with anger, Prax opens the next door to find a group of security guards taking a break. Prax, hysterical, inadvertently starts a gunfight. The group presses on and finds more security guards and a secret science lab with the black tendrils of the Protomolecule. Holden then calls Naomi telling her they have to leave immidiately.
The System WarEdit
After the Ganymede incident, Meng became a prominent figure in the moon's reconstruction.
During the War, Prax worked on and surreptitiously released a modified yeast containing an artificial chloroplast reverse-engineered from the protomolecule to make energy from a wider range of radiation than natural flora.