Except how? Formaldehyde is actually a colorless gas, primarily used in aqueous solutions for preserving specimens. In addition to being poisonous in high enough concentrations, it can negatively impact the upper respiratory system and irritate the skin and has been linked to several kinds of cancer. Needless to say, safe disposal of formalin solutions generally involved identifying the solution as a hazardous waste and following proper protocols.

But I couldn’t risk being documented turning over hazardous waste.

The easiest thing would be to dump the clear solution down the drain, or flush it down the toilet, relying upon the city’s water system to successfully dilute the relatively small amount of formaldehyde. Unfortunately, I wasn’t sure if that was foolproof from a forensics point of view. For one thing, the pungent smell might linger, a particular odor no one would mistake for toilet bowl cleaner. Also, later on, should my sister’s scheme lead to a law enforcement sweep of my home, would they be able to still determine even a trace of formaldehyde in, say, the ring around my sink, or trapped in my pipes? I honestly didn’t know; such things never came up in medical school.

I would have to remove the solution from my unit. Take it elsewhere for disposal. As well as the strips of skin, the glass vials, the box.

A mall. A large public space where I could visit many stores as well as public bathrooms without arousing suspicion. Maybe discard one item here, one item there. Then maybe a trip to the grocery store. A woman, just running her errands.

It could work. As long as I was calm and inconspicuous, and remembered there were cameras everywhere. If there was one thing I had learned from my sister over the years, the best deceit was covered in layers of truth. Of course I went to that mall with the Ann Taylor store. Of course I picked up milk and bread. Why wouldn’t I do those sorts of things?

A rough plan forming in my mind, I took a calming breath and got to work.

Latex gloves. A larger, single glass container to hold all the formalin solution, maybe a mason jar? But that would look strange. Anyone who saw a woman walk into a public restroom with a glass jar filled with a mysterious liquid, especially in Boston, post–marathon bombings . . . Not going to work.

Stainless steel water bottle. I had four or five in my kitchen cupboard. I picked my least favorite, an innocuous metallic blue with black top, which I placed on the bathroom counter to my right. Added to that a quart-size sandwich bag, opened to my left.

Single strip of skin placed in the ziplock bag. Couple of tablespoons of solution poured into the water bottle. Quick work, really. A decade of collecting dismantled in less than fifteen minutes.