The Argentine El Tunel features two of that country's brightest young stars, Laura Hidalgo and Carlos Thompson (the latter was on the verge of "going Hollywood" in 1952). Based on a controversial novel by Ernesto Sabato, the film attempts to probe the psyche of a demented murderer. Thompson plays a surrealist painter who falls in love with the wife (Hidalgo) of a famous pianist. Consumed by jealousy of the woman's multiple affairs, the painter is driven to murder. But that's only part of the story: once he's safely ensconced in a lunatic asylum, the artist is "interpreted" by a group of self-styled specialists, in much the same way as his paintings had previously been picked apart by art critics.
~ Hal Erickson, All Movie Guide