A group of scientists anxiously await word for a despondent, melancholic patient named Claude Ridder (Claude Rich) to regain consciousness at an unidentified hospital, where he is gradually recuperating from a gunshot wound resulting from an attempted suicide, in order to approach him on an ambiguous proposal to participate in a short duration human time travel experiment. Arriving at Crespel Research Center, Ridder is escorted on an introductory tour of the facility by the director Jan Rouffer (Van Doude) who brings him before a pair of laboratory glass belljars containing a control mouse 'A' and subject "pioneer" mouse 'B': the latter rodent having successfully (but unverifiably) undergone a one-minute temporal regression - the apparent durational limit of the experiment - at precisely 4:00 p.m. a day earlier. In an attempt to validate the results of the test run, Rouffer has turned to Ridder for verification, asking him to become the first human subject of their experiment and provide first-hand observations and corroborative biofeedback data under the presumption that his disregard for his own life would make him a suitable candidate willing to accept the risk for such an unprecedented (and uncertain) journey in exchange for reliving a life episode of his own choosing. Ridder has a specific moment in mind to relive for the occasion: emerging from the ocean on the Riviera a year earlier from an afternoon of snorkeling to the sight of his lover Catrine (Olga Georges-Picot) lazing on the shoreline. However, shortly after the start of the test, the scientists experience a malfunction in the release mechanism process of the voluptuously organic time travel apparatus, consequently trapping Ridder into an isolated world of his own fractured, infinitely repeating memories.

Realized from a five-year collaborative project with novelist Jean Sternberg, Je t'aime, je t'aime is a structurally complex, yet visually refined, emotionally cohesive, and lucid exposition on guilt, desire, longing, and regret. Through dissociative and achronological personal memories that contextually illustrate Ridder's turbulent, long-term relationship with Catrine, his uninspiring desk job (and mediocre career success) in publishing, and ambiguous, interrelated events that foreshadow his attempted suicide, Alain Resnais captures the seemingly mundane rituals of everyday life - what the filmmaker describes as temps morts (literally, dead time) - that intrinsically define the essence of human existence. Recalling the interplay of role, identity, and memory of Resnais' earlier films, Hiroshima mon amour and Last Year at Marienbad, the film is also an exploration of identification and existential validation. However, in contrast to the grandiosely formalist - and consequently, aesthetically artificial - and irresolvable logic puzzle of Last Year at Marienbad with which the film shares a similar asequential structure and dislocated (and overarchingly recursive) narrative, Ridder's unremarkable life is presented in terse and abstract episodes that, although also eschewing narrative, inherently illustrate a complexity of form, experience, tactility, and emotional realism. In the end, it is the film's organic ability to convey depth and texturality that elicits pathos and humanity for the deeply flawed, alienated, modern day tragic hero imprisoned by the eternal torment of his inescapable, haunted memories.