This is the story of a Passover that I remember every Passover, and a seder night that both haunts and comforts me. Let me take you back four years.

“It smells of sweet corn,” the doctor said to me as I gathered the mountainous reams of paperwork that constituted my wife’s ever-growing medical records.

“I beg your pardon, what smells of sweet corn?” I asked, knocking the file down on the table as though shuffling a giant deck of cards.

“The transplant.” She said. “It smells of sweet corn, it’s a very distinct smell, but she won’t be able to smell it. Strange but true,” she explained, as she gestured toward the door of her small office on the second floor of Haifa’s Rambam Hospital. It was check-in day for my wife Yael, who was suffering from a relapse of Lymphoma and preparing to undergo a stem cell transplant.

We were well-prepared. Our bags were full of DVDs, a selection of pajamas and headscarves. Our two young boys were at home in Modi’in with our parents, freshly flown in from London, and she had kissed them goodbye: for a month, perhaps only for three weeks, maybe forever. But we had a bag full of DVDs, headscarves and pajamas, so, as I said, we were well-prepared.

As I exited the small office, clutching a folder full of blood-test labels, graphs, charts and illegible notes, I had it all sorted out. Yael was going to have treatment, our parents would look after the kids and there was going to be a smell of sweet corn.

I donned the bizarre shower cap style shoe covers, fumbled into some stiff blue scrubs, doused my hands in alcohol rub and – eyes stinging from the overwhelming smell of bleached sterility – made my way through the airlock double door at the entrance to the isolation ward.

That it was Passover in just a few days, made no difference to the level of cleanliness in the ward. As dangerous as chametz (leavened bread and grain products) may be for the soul, bacteria here was lethal. As I went through the rituals of hospital purification, I ran through in my head the spiritual preparations we had made in cleaning for Passover. With house cleaned and chametz sold, I had packed – alongside the headscarves and DVDs – a plastic seder plate, a freezer bag filled with matzah, grape juice, a burnt egg, bitter herbs, charoset and two haggadot. I even had a feather and candle for Bedikat Chametz (the ritual search for leavened bread).

Being away from the kids for Passover, and especially seder night, for any reason is difficult. Yet despite all our preparations and pretense, this was almost too hard to hard to bear. And as we readied the small isolation room for the beginning of the festival, tears filled our eyes.

We cried for the illness that was eating away at Yael from inside, for the brutal treatment that had taken her beautiful hair, for the operations and biopsies that had scarred her skin, but above all, for our children, who were a hundred miles away on the night we should be hearing them ask ‘The Four Questions.’

‘When is Mummy coming home?’ is not meant to be one of the questions asked on seder night. However, knowing that, as planned, they were with their grandparents and cousins, we forged on. Yael lit the candles to begin the festival and I made my way to the hospital synagogue for the evening prayers.

When I returned, Yael was feeling quite sick, but was, despite it all, ready to make a seder. Needing a small cup for the salt water, I ventured out to the nurse’s station to ask for one of those small plastic cups used to distribute tablets, and as I did, I heard a deeply accented American voice call out in Hebrew, “Are you the Rabbi?”

I turned to see a young woman resting in a wheelchair at the entrance to one of the rooms. I explained I was not, but my wife and I were about to do a quick seder and – as Yael was not yet in total isolation – if she could, she was welcome to join. So she did.

We hadn’t planned this. We had headscarves, pajamas and a seder plate… but we hadn’t expected company.

I often wondered under what circumstances I would be able to invite someone to seder without it being planned weeks in advance. We read every year “all who are hungry, let them come and eat,” yet never, in my middle class ‘Passover-shopping-starts-at-Purim’ world, did I ever think I would have the honor of welcoming a stranger, unannounced, to my seder.

Moreover, that year more than any other, I had thought the planning and preparation would be what got us through. I thought the number of headscarves, the fresh pajamas, the DVDs, and the perfectly planned seder plate were our get out of jail cards. We knew what was coming, so everything would be all right. Yet it was the surprise visit, the unplanned guest, who provided the spark that made that difficult night so special. As we sat there in the isolation ward, we discussed how, with God’s help, the Jews came out of Egypt and how Yael and our visitor were coming out of cancer.

A few days later Yael had her transplant. In truth of course, we had no idea what would happen. But as promised, the smell of sweet corn filled the room and lasted for days. Within a few weeks she was home. It was far from the best Passover ever, but its lessons stay with me as strong as the memory of that smell. And while I can never again eat sweet corn – I still love seder night.