While my dad and I ferried boxes and luggage from the elevator, my stepmom, Terry McLean, surveyed her temporary Toronto digs from the couch: a cramped, dimly lit two-bedroom apartment decorated in mauve, black and gold and smelling vaguely of cat pee. “Can you crack a window?” Terry asked me. “I feel like I’m in a witness protection program in here.”

I opened the curtains and slid back the balcony door, the June heat billowing into the apartment. In a rush to move from Quebec’s Eastern Townships to Toronto, my dad had failed to notice that their new home on McCaul Street was next to a construction site and directly above a TTC loop. Standing there, the building thrumming with jackhammers and the screech of streetcars, I suggested things might be better with the curtains closed. My dad, Ashok, had taken a seat on the couch, his arm around Terry. Her face had changed; the sarcasm was gone. On the floor between them, the oxygen compressor that kept her breathing—imagine the robot love child of R2-D2 and Darth Vader—hissed and puffed. Terry looked around the apartment again, then pulled the tubes from her nose and leaned into him. “Don’t let me die here,” she begged my dad. “Please.”

In February of 2005, at age 58, Terry was diagnosed with broncho­alveolar cancer. BAC is a rare form of adenocarcinoma that tends not to spread beyond the lungs and is therefore open to a range of treatments. The initial diagnosis was complicated by the fact that for 25 years, Terry had been living with pulmonary sarcoidosis, a relatively benign lung disease that often appears in lumps similar to cancer cells. After biopsies confirmed BAC, surgeons at Jewish General in Montreal removed the affected lower lobe of Terry’s left lung—the hope being that the cancer would be removed, too.

For the next six months, while the scar from the surgery—puckering in a long pink slice from her right shoulder to her left hip—healed, she under­went chemotherapy. This resulted in the usual fatigue and hair loss (after test driving a wig for a bit, Terry opted for hats). But in September, at the end of the meds cycle, a CT scan showed that the BAC had returned. A non-smoker, in otherwise incredible shape (before getting sick, she regularly ran half-marathons), Terry could only listen, baffled, when her Montreal respirologist, Dr. James Gruber, chalked the recurrence up to simple bad luck.

A course of new, experimental drugs only seemed to further compromise Terry’s health. Unable to return to work at Douglas Hospital in Montreal, where she coordinates a psychiatric education and research program my dad runs through McGill University, she spent the following three months approaching household chores with steely resolve, often collapsing in a fit of coughing. In January, when it became impossible for her to climb more than two stairs, Terry was prescribed an oxygen unit and a regular supply of canisters. Still, despite her steady deterioration, she maintained a spirit that was half heroic and half stubborn resilience; vacuuming became a torturous form of exercise, followed swiftly by several minutes of oxygen. Later, when I asked her what kept her going, she said, “I wanted to live.”

“Why, though?” I pressed. “What made you want to live?”

Without a second thought, she said, “Ashok.”

I was 10 when my parents divorced, and 15 when my dad married Terry. The elder brother to two sisters, Cara and Anna, I suddenly became the middle child; any authority I had was usurped by Aaron and Regan, my two older stepbrothers. My sisters and I spent alternate weeks at my dad’s, a situation I struggled with throughout my teens. I was distant, going through the motions of family life but never really feeling engaged, struggling to think of his and Terry’s house as home.

In my last year of high school, a friend of mine was over, waiting with my dad and Terry in the kitchen while I got myself ready to go out. In the car, she described how they had sat with their pinky fingers entwined while chatting with her. “Ashok was so cute! They’re so in love!” she gushed. At the time, this was nothing I wanted to hear. But 10 years later, it’s a memory that’s come fluttering up from somewhere to hover over recent events.