Scientists have said that smell is the sense tied most closely to memory. In my experience, there are many smells, like those of citrus and cookies, that take me to a wonderful time and place. There are other smells, like those of vomit and blood, that I would just as soon forget. I hadn't been working in the emergency room for long when I first met a very memorable odor.

The nurse had told me to flush the laceration on the woman in bed 27. Since the cut was on the back of the woman's head, the nurse added that I would also need to shave some hair away so the doctor could better see the area. Fair enough, or so I thought. I walked into the room, my hands brimming with supplies-a bottle of saline, a sterile bowl, a 10 ML syringe, a splash guard, a razor, and some medical scissors and tweezers. I was not entirely prepared for what met me at the door.

It was the smell of infection, greeting me with its outstanding signature. It is a vile, biting, rancid odor. The relatively small wound on this woman's occipital was a factory for an invisible cloud of penetrating foulness. It lurked in the room and dared for me to challenge it. Instead, I politely smiled and set my supplies on a metal stand next to the bed. It clanked a bit as I moved it away to brave the Smell and investigate the source.

The woman lay on her side, head under a chux, the goofy smile of a narcotics lightweight on her face. I grabbed a pair of green latex gloves and stepped behind her as she spoke to me. She told me she had injured herself a week ago, but the hospital she had gone to didn't suture the cut. It was now, very noticeably, a problem. I gently touched her crown and braced myself as I lifted her brunette hair away and peered closer. Her hair was matted and stuck to the slice. The wound was chunky with the products of infection and the Smell poured from it like rainwater from a clogged gutter. I smiled, then politely excused myself for one last necessary supplement to my basic irrigation kit.

I walked out of the room, gasping for air. I rushed to the medication room, only a few steps away, and searched the crowded shelves of sterile water and lidocaine for a tiny, otherwise inconsequential, bottle of peppermint essential oil. That vial of compressed mint was my own personal savior. Within seconds, I had snatched it from its shelf, impressed the childproof cap, and twisted the bottle open. I tipped the top onto my finger and rubbed the cloudy oil inside my nostrils. Peppermint is deeply beautiful and relieving. Its soothing, deodorizing properties were, perhaps, only amplified by the terror I had just inhaled. This was my only defense against the Smell and, armed now with a few drops on my clothing, I returned to face the infection.

I assembled my supplies like a seasoned solider preparing for war and pushed saline through the open wound one syringe at a time. The water splashed and drained down the woman's head, carrying all sorts of particles with it. I carefully navigated the razor around the perimeter and scraped away the matted hair. After 15 minutes and a bit of tidying up-picking up wet towels, used supplies and trash-I proudly walked out of the room to report my efforts to the doctor. My actions had not been particularly noteworthy, but what mattered was I had conquered, and instead of infection, the Smell was now victory.