An important character in the Novacom saga, Monica Stone was a spy for Novacom Enterprises. She and Robert Mitchell are the two direct employees of Novacom to join for somewhat noble reasons. Although one-dimensional throughout her early scenes, the truth why she worked with Novacom added complexity to her role, as well as the overall theme of the Novacom saga.
Monica's Work within Novacom
Monica worked primarily with illegal activities. Disguised as a female phone company employee, Monica placed hidden cameras in Whit's End. After this plan was foiled, she attempted to intercept a package sent to John Avery Whittaker, owner of Whit's End, holding him (and Jack Allen) at gunpoint. (The package was later found to be a decoy.)
Monica tapped Eugene Meltsner's phone-line and learned that he would be sending a package to Jason Whittaker, son of Mr. Whittaker, who was in Alaska. She followed the package, posing as an intern for Around the World Missions. Jason presumably fell in love with her, as they worked together closely. When Jason realized she had taken the package, he tried to stop her, and she gave back the disk - after she had emailed the contents to Novacom. Jason was crushed to find out she was a spy. Jason then mailed the package to Whit back in Odyssey.
Fallout with Novacom
In the episode #496: “Exceptional Circumstances”, it is learned that Monica was willing to work with Novacom, including participating in illegal activity to help her paraplegic brother Duncan Mathis, whose condition was due to a diving accident she had a part in. Monica believed that Novacom would help to heal Duncan if she did their dirty work, so she agreed to it. However, Mr. Charles, Monica's superior at Novacom, turns against her when she began to question whether or not they would. She then stands up against him when he tries to intimidate her with jail threats, severing her employment with Novacom.
The last we hear Monica is in Exit, the final Novacom episode. She was going on trial for working with Novacom, but she said she already knew how it would turn out. Jason said he would visit her in prison. Monica asked if he would bring flowers, and he replied, "Maybe on Valentine's Day."
Monica has a brother named Duncan Mathis. Because they both have different last names, it can be inferred either that at one point she was married, Duncan is her half or step brother, or "Stone" is part of an alias for her work with Novacom. (Something interesting to note is that when Mickey Marcus went to Israel, he went under the name 'Mickey Stone'.)