Set fifteen years in the then-future year 1983, the series tells the tale of the crew and passengers of a sub-orbital transport ship named Spindrift. In the pilot episode, the Spindrift is en route from Los Angeles to London, on an ultra-fast sub-orbital flight. Just beyond Earth's boundary with space, the Spindrift encounters a magnetic space storm, and is dragged through a space warp to a mysterious planet where everything is twelve times larger than on Earth, whose inhabitants the Earthlings nickname "the Giants". The Spindrift crash-lands, and the damage renders it inoperable.

When an assassin's bullet confines him to a wheelchair for life ending his career as Chief of Detectives, Robert T. Ironside becomes a consultant to the police department. Detective Sergeant Ed Brown and policewoman Eve Whitfield join with him to crack varied and fascinating cases. Ex-con Mark Sanger is employed by the chief as home help but eventually becomes a fully fledged member of the team also. Officer Whitfield leaves after 4 years service, and is replaced by Officer Fran Belding.

In prohibition-era Chicago, the corrupt sheriff and Guy Gisborne, a south-side racketeer, knock off the boss Big Jim. Everyone falls in line behind Guy except Robbo, who controls the north side. Although he's out-gunned, Robbo wants to keep his own territory. A pool-playing dude from Indiana and the director of a boys' orphanage join forces with Robbo; and, when he gives some money to the orphanage, he becomes the toast of the town as a hood like Robin Hood. Meanwhile, Guy schemes to get rid of Robbo, and Big Jim's heretofore unknown daughter Marian appears and goes from man to man trying to find an ally in her quest to run the whole show. Can Robbo hold things together?

A series of unrelated stories containing drama, psychological thriller, fantasy, science fiction, suspense, and/or horror, often concluding with a macabre or unexpected twist.