John Phillip Law and Marisa Mell in Diabolik.

Overworked, distressed by personal problems and upset by the death of his father and mentor in October 1966, Bava avoided the genre for the next two years. He was lured back to work when Dino DeLaurentiis offered him the biggest assignment of his career, Diabolik [Danger: Diabolik, 1968], based on the Giussani Sisters' popular fumetti. Budgeted at $3,000,000, Diabolik was completed by Bava for only $400,000. One of the finest comics adaptations ever, Diabolik was enormously lucrative in Europe. Accustomed to the freedom that came with budgets of under $150,000, Bava found that he disliked the production office interference and other pressures that came with hardball budgets, and politely declined DeLaurentiis' invitation to helm a sequel. Bava healed from the experience in a hidden capacity, collaborating with Carlo Rambaldi on the special effects for the miniseries Odissea (1968). Afterwards, Bava happily withdrew to "slumming" in more familiar territory, directing the darkly ironic psycho-thriller Il rosso segno della follia [A Hatchet for the Honeymoon, 1969] in Barcelona.

Bava next suffered the humiliation of painting a moustache on his masterpiece Lise e il diavolo in an effort to recover its $1,000,000 cost. The sad result was La casa dell'esorcismo [The House of Exorcism, 1975], a bewildering, johnny-come-lately Exorcist rip-off combining Lise footage with pea soup, priestly guilt and blasphemy. Once again, Bava's boldly original work was packaged with the title of a second-rate imitation.

With a string of failures, misfires and also some non- paying successes behind him, Bava was also finding it harder to work after turning 60. Troubled by his father's inactivity, Bava's son Lamberto (his assistant director since 1966) scripted what proved to be his final feature, Schock [Shock, 1977]--the harrowing story of a woman's mental collapse after returning to the house where she once lived with her late, drug-addicted husband. Bava storyboarded the entire film but directed only parts, feigning illness to help Lamberto gain some directorial experience. The Italian master of illusion was becoming disillusioned with the business of making movies. In America, this original story was retitled Beyond the Door II.

Father and son next shared directorial credit for a lovely adaptation of Prosper Merimee's fantasy La Venere d'Ille ("Venus of Ille," 1978), shot in 16mm for RAI-TV. Even this swan song success found a way to disappoint its maker, remaining unshown for two years, and premiering after Bava's death.

Bava's last assignment was working as an uncredited special effects designer on Dario Argento's Inferno (1980). Mario built maquettes, painted glass mattes and devised optical effects for the film, including its momentous lunar eclipse. As Argento now admits, Mario also directed certain scenes in his absence when he was stricken with hepatitis.