The Starfleet ship whose visit to Sigma Iotia II, and a forgotten book, reshaped the planet's culture.
The USS Horizon was a Starfleet ship that visited the planet Sigma Iotia II about a century before 2268, before Starfleet's non-interference directive, when the native Iotians were highly imitative. The crew left behind several books, among them a history of Chicago gangs in the 1920s.
The Horizon was lost shortly after the visit, and its report reached Starfleet only a century later by conventional radio. When the Enterprise investigated in 2268, it found that the Iotians had modelled their entire society on the gangster book, which they treated as a sacred text.