Quo vadis?
Quo vadis? (Classical Latin: [kʷoː ˈwaːdɪs], Ecclesiastical Latin: [kwo ˈvadis]) is a Latin phrase meaning "Where are you marching?" It is also commonly translated as "Where are you going?" or, poetically, "Whither goest thou?"
The phrase originates from the Christian tradition regarding Saint Peter's first words to the risen Christ during their encounter along the Appian Way. According to the apocryphal Acts of Peter (Vercelli Acts XXXV; late 2nd century AD), as Peter flees from crucifixion in Rome at the hands of the government, and along the road outside the city, he meets the risen Jesus. In the Latin translation, Peter asks Jesus, "Quo vadis?" He replies, "Romam eo iterum crucifigī" ("I am going to Rome to be crucified again"). Peter then gains the courage to continue his ministry and returns to the city, where he is martyred by being crucified upside-down. The Church of Domine Quo Vadis in Rome is built where the meeting between Peter and Jesus traditionally took place.
The words "quo vadis" as a question also occur at least seven times in the Latin Vulgate.

Meaning as used idiomatically
When used idiomatically, in ordinary day-to-day language, the phrase usually is spoken or written to inquire about someone's purpose, ambitions, or decisions in a particular situation. It may also be employed to encourage introspection or to express surprise or confusion regarding someone's actions or decisions. In general, this phrase prompts individuals to consider their direction and purpose [especially when questionable], urging them to reflect on their goals or to assess the consequences of their choices.
The phrase has also been used in academic papers. For example a paper on the drug Remdesivir wonders on the future direction the drug Remdesivir is taking in view of doubtful results, and frequent side-effects.

In culture
The Polish writer Henryk Sienkiewicz wrote the novel Quo Vadis: A Narrative of the Time of Nero (published in installments between 1895 and 96). The book in turn has been made into motion pictures several times, including a 1951 version that was nominated for eight Academy Awards.  For this and other novels, Sienkiewicz received the 1905 Nobel Prize for Literature.
In a season four episode of M*A*S*H entitled "Quo Vadis, Captain Chandler?" the reference pertains to Jesus Christ. A shellshocked officer arrives at the hospital believing he is the Christ. He has numerous conversations with the characters, including Father Mulcahy. He ultimately leaves the MASH unit for an evacuation hospital, still unrecovered.
Quo Vadis, Aida is a film about the Srebrenica massacre by director Jasmila Žbanić.
Quo Vadis has also been used as a name by many companies and groups. Quo Vadis is the name of a restaurant in London. A students’ club at University of Pittsburgh, established in 1944 to give tours of the Nationality Rooms, is called Quo Vadis.

References
External links
 The dictionary definition of quo vadis at Wiktionary
 Media related to Quo vadis at Wikimedia Commons