Roma is the name given to the hacker on Ganymede for the TV adaptation. For the incarnation in the book series, the character is unnamed.
This man is an unscrupulous opportunist. In the aftermath of the orbital mirror collapse over the station which immediately crippled two environmental domes, he exploited the survivors, accepting favors for his electronic infiltration skills as required to locate missing family members.
When Prax and three of our protagonist crew arrive at Ganymede station in search of clues that will reveal the locations of both Strickland and Mei, they split into two parties. Amos accompanies Prax and together they encounter an acquaintance of his, Basia. After overcoming a misunderstanding and some pent up frustration, Basia determines it would be beneficial to send both of them to the guy he had been seeking help from already, Roma. Basia is quick to inform them that Roma finds video and works for food but he likes chicken and canned chicken best.
When Naomi and Holden rejoin them, they head for Roma's place passing a woman abruptedly leaving the residence in a state of undress and canned food in her arms. Holden inquires about the hacker by name but the shirtless man is reluctant to identify himself until after Holden divulges that he was referred to him as someone who finds people. Roma's eyes widen and his grin grows wide at this opportunity to profit.
The group enters the residence and Holden shows Mei's picture to Roma using his hand terminal. Roma comments that the little girl is pretty. Roma says something about Jim looking for Mei that could be interpreted as inappropriate but Holden ignores it. Roma demands chicken. The hacker presses for compensation and emphasizes that's what he likes and for a girl like Mei it's going to take a lot. Roma has pegged them as being fat-pocketed. Naomi asks for some guarantee which he flatly refuses so, she remarks about how reliable he could be. Amos remarks on the abundant supply Roma already has and the capacity to feed half the starving station. Roma demands that Amos returns the can of chicken he's pick up back in its place. Jim suggests other items they might be able to trade. Roma comes back with an ultimatum again demanding chicken.
Amos explodes and repeatedly beats Roma in the hacker's temple with a can. Holden doesn't restrain him. Aghast, Naomi attempts to intervene but Holden does restrain her. Prax finally gets between Amos and proclaims the guy can't help if Amos beats his head in. Amos relents but withdraws the gun from the hacker's pants waist. Amos leans in, cradles Roma's head, points the guy's own weapon under his chin, and asks again in his ear if the hacker will help them find the little girl. Breathing heavily, Roma yields, nods profusely and declares he'll even do it pro bono.