Synopsis

At 44, Agathe (Marie-Ève Perron) has her life fairly well ordered. Despite being separated for seven years from Élizabeth (Amélie Dallaire) — with whom she co-parents their charming 11-year-old daughter, Charlotte (Agathe Ledoux) — she has found a peaceful balance. But that stability is shattered when Agathe notices severe swelling in her left breast. A painful mammogram and subsequent biopsy confirm her worst fear: cancer. The ground gives way beneath her — and the abyss only deepens when Samuel (Gabriel Lemire), her partner of five years, abruptly walks out.

This sudden abandonment forces Agathe to lower her guard and lean on her fiercely loyal inner circle (Kathleen Fortin, Julie Roussel, Ariane Castellanos, Marie-France Moreau and Sophie Desmarais). Her lifelong nickname — “Miss ‘I’ve Got This’” — is put to the ultimate test as she is thrust headfirst into the bewildering world of oncology while still in deep denial. The battle before her grows monumental; endless appointments fill her days, and medical jargon quickly becomes her second language. In a desperate bid to survive, she must now endure a double mastectomy and the grueling physical toll of aggressive chemotherapy and radiation to combat a staggering diagnosis: not just one cancer, but three.

One might assume this illness would strip Agathe of everything — her health, her career, her relationship and her daughter’s innocence. Yet, the exact opposite happens. Over nine months of intense treatment, Agathe learns to set boundaries, advocate for herself and truly embrace the power of her support network.

Le gouffre lumineux is a deeply moving, dizzying descent into a patient’s psyche. It's a story of personal and medical resilience where clarity and denial, heartbreak and devotion, and unexpected moments of joy beautifully intertwine.