The last film Tarkovsky completed in the Soviet Union was "Stalker", inspired by the novel "Roadside Picnic" by the brothers Arkady and Boris Strugatsky. Tarkovsky had met the brothers first in 1971 and was in contact with them until his death in 1986. Initially he wanted to shoot a film based on their novel "Dead Mountaineer's Hotel" and he developed a raw script. Influenced by a discussion with Arkady Strugatsky he changed his plan and began to work on the script based on "Roadside Picnic". Work on this film began in 1976. The production was mired in troubles; improper development of the negatives had ruined all the exterior shots. Tarkovsky's relationship with cinematographer Georgy Rerberg deteriorated to the point where he hired Alexander Knyazhinsky as a new first cinematographer. Furthermore, Tarkovsky suffered a heart attack in April 1978, resulting in further delay. The film was completed in 1979 and won the Prize of the Ecumenical Jury at the Cannes Film Festival.