Sergio Sollima didn’t direct very many films. His career is split fairly evenly between theatrical and televised fare. Devil in the Brain is not what anyone would consider a technically outstanding movie, but it is solid in its craftsmanship.
Had Dark Purpose been an hour long episode of a TV show, it would have delivered. But forced to come up with, roughly, three half-hour acts, it can’t sustain the momentum and Shirley Jones, while perfectly acceptable, just isn’t dynamic enough to make us forget nothing much is going on.