Richie Adler (Matthew Laborteaux) lives with his mother and sister; his parents are divorced, and his father works overseas, often in the Middle East, as a telecommunications engineer/consultant to several firms located there. Richie is an advanced computer user with cutting edge skills. Presumably he has inherited these abilities as well as most of his computer equipment from his father. He acquires obsolete equipment that was scheduled to be scrapped and sends it to Richie. He even sends a programmable robot, Herman. Richie collects this equipment and connects and assembles it to form RALF, his pet name for his computer system. RALF has multiple components and capabilities, including a camera which produces a primitive facial identification system.
Richie and his friends come across mysteries which they (mainly Richie) attempt to solve using his computer skills with RALF's power. Guidance is often provided by newspaper reporter Farley (their mentor). The cases often involved money-hungry criminals working inside business or government who would assault and murder people to cover-up their deeds. There were also a few episodes involving spies of the Soviet Union.
Lew Farley (Max Gail) is a reporter for the fictional newspaper the LA Gazette (although on the first episode the reporter is named Gallagher and he is played by Michael Horton). Many of his stories are exposés of crime and corruption. He is well connected and seems to know everyone from gangsters to beat cops to a mysterious patriarch. He has a cantankerous but mutually beneficial relationship with Lieutenant Quinn (A Martinez) who is head of the detective unit, and also married to Farley's sister. Farley was a Vietnam-era anti-war protester who was jailed and beaten on occasion during marches. He was inspired to journalism by a woman whose death he investigates in "The Wrong Mr. Wright".
Farley is somewhat technologically capable (carrying around one of the first laptops ever sold, a Gavilan SC), but he relies on Richie for complicated technical help. He warns the Whiz Kids of danger and helps them when they get in over their heads with criminal elements or with the government. He is often the first person they call when they are trouble, and Richie's mother leans on him as well.
In most episodes, the three groups -- the police (mostly led by Quinn), the media (usually Farley), and the Whiz Kids -- wind up all contributing to cracking a case and in bringing the criminals to justice. Their relationship is often conflicted, as Quinn must keep Farley from getting too much insider information, while Farley and Quinn must keep the kids out of danger. However, each case is never solved by one group alone, and they are all usually forced by circumstance to work together, each drawing on their own particular strengths.
Richie's father is a telecommunications engineer who often works abroad and is mostly absent. He does drop in town occasionally, however. He is well connected in high level Washington political circles, something that Richie's mother alludes to and uses. Richie's mother and father are divorced, but their relationship is portrayed as still positive and friendly. She also keeps his name and refers to herself as Mrs. Adler. She says that she thinks his job-required traveling is what led to their divorce.
Richie's mother is somewhat strict and does not allow his genius level abilities to influence her duty as a mother. She makes him clean up the messes he and his buddies cause with their various hijinks, and she does not let him shirk his schoolwork, chores, or other responsibilities. (Nor does his teacher: in "Red Star Rising", their being applauded by the CIA does not get three of them off the hook for not completing a homework assignment - Alice is spared, since she actually did it!) Richie's little sister Cheryl provides comic relief in most episodes, but she does have a few important scenes of insight or family drama.
There is a slight love triangle between Richie, Ham, and Alice. Alice is a bit of a hacker herself, but she receives little respect or extra attention from Richie, which bothers her greatly. Ham really likes Alice, but she (for the most part) does not return his attentions.
On the whole, the teens do not get a whole lot of character development. Most of the episode time is taken dealing with the complicated plots, criminals exposition, Lew and Quinn, chase scenes, and hacking scenes (which are almost totally focused on Richie). However Jeremy is shown to be rather clever in his own right and the kids are involved in many activities, including go-kart racing, sports, ballet, and music. There is also a bit of a conflict between Richie and the others, as he can sometimes be domineering or arrogant, although they typically reconcile.