Originally a thriller novel by Patricia Highsmith (incidentally also the author of 'The Talented Mr. Ripley' for a more contemporary referent), 'Strangers on a Train' was adapted by Alfred Hitchcock into a movie about two complete strangers, who, upon their chance encounter in the train, each going on to confess fantasies about murdering someone in their lives, drawing up plans for a fantasy double murder.

After the Hitchcockian novel of the same name, the 'Strangers on a Train' phenomenon refers to the strangely honest bond forged by strangers under circumstances markedly different than those afforded by the quotidian

Social opportunities created by travel, where virtual strangers are thrown into a series of serendipitous meetings and intelligent networks with the characteristic honesty illustrative of the phenomenon (double murders not withstanding).