In the final chapter of Mary Kills People, we pick up five months after the events of Season 2 and Mary is ostensibly at peace. The police investigation into her actions came up empty, her days of constantly looking over her shoulder appear to have passed, and the hospice she started with Des – their dream of a safe and secluded retreat where they can tend to terminal patients without risk of exposure – is up and running. Mary and her daughters are busy preparing for the arrival of her baby – a warm, new beginning in contrast to the harsh winter snow and ice that has encased Port Denver.

But as the season unfolds, we learn Mary is deeply conflicted. Was her choice to raise her baby alone the right one? Is Des’s system of orderly deaths at the hospice enough? What about the other terminal people in the world who need her? Mary’s doubts are put on hold when she encounters an ICU nurse with a secret Mary understands all too well. Both women believe that the terminally ill should be able to die on their own terms – but as they become entangled in each other’s lives, Mary learns that they’re governed by very different rules of mercy. And as this latest threat grows and a new police investigation is opened, Mary finds herself needing the one person she knows she can’t face – Ben.

Fear, mercy, death, and reckoning await in Mary Kills People Season 3. And the question asked three seasons ago – when Mary and Des first jumped off Troy Dixon’s balcony – will finally be answered. How far is Mary willing to go for her cause?