Dr. Timothy Francis Leary Jr. was a psychologist, lecturer, author and advocate for both the therapeutic and recreational use of psychedelic drugs. George Gordon Battle Liddy was a lawyer and bagman for President Nixon who went down for his involvement in the Watergate scandal. Both did some time in prison and that is the genesis of their improbable friendship. Both men ended up as inmates at Terminal Island Federal Correctional Institution in California.
For his involvement in the burglary of the DNC offices, Liddy was convicted of conspiracy, burglary and illegal wiretapping. He was sentenced to 20 years in Federal prison in 1973. President Jimmy Carter commuted his sentence to 8 years in 1977. The commutation made him eligible for parole and he was released in 1977 having served 4 and a half years. More here.
Leary was arrested in 1965 for drug possession following a raid orchestrated by Liddy. Following a similar arrest in 1968, he was sentenced to 10 years in 1970, with a further 10 added for a prior arrest in 1965 to be served consecutively. (The 1965 conviction was later overturned by the Supreme court) Leary escaped from jail and fled to Algeria and then Switzerland. The Swiss briefly imprisoned Leary but refused to extradite him. He traveled to Austria, Beirut and was eventually arrested in Afghanistan. Leary was released from prison on April 21, 1976 by Governor Jerry Brown. More here.
By 1981 both Leary and Liddy had re-entered the public sphere as guest commentators on morning radio programs and talk shows. (Leary can be heard on some rare CBS transcriptions of the program "Rock Connections." ) After a speech at the University of Texas at Austin in 1981, Leary ran into Liddy. To exploit their opposing backgrounds and viewpoints Liddy joined with Leary for a series of debates at college campuses. Those tours continued through at least 1984. The debates were the topic of a documentary film in 1982 titled the Return Engagement.