"Mrs. Gaynes. Your son. I'd hate to think you're impeding our investigation. We are trying to help him, you know. We're trying to protect him from some very bad people."

The old woman's lip quivers. Her brows darken.

"You leave him alone," she hisses. "He's a good boy. He sends me money."

"Money. How much money?"

"Enough for my treatments."

"Do you know anything about a suitcase? A metal suitcase?"

Fidgeting with the oxygen tube, Mrs. Gaynes shakes her head no.

Harriet finally moves. She doesn't move swiftly; she simply approaches and enters the woman's personal space. Her knees nearly touch the oxygen tank. Harriet folds her hands in front of her.

"I see you're on oxygen," she says.

"I told you, emphysema. Got it from smoking. Most of my lung capacity is gone. Got about twenty percent left, the doctors say. You can't get it back, they say. Damn doctors."

"You need the oxygen to breathe."

Mrs. Gaynes picks at the fraying edges of the blanket across her lap. "That's the idea." The words come out sarcastic and bitter.

"Interesting fact about oxygen," Harriet says, "as I'm sure you're aware from the many warnings on the tank and nozzle–"

Harriet pulls out a Zippo lighter with a paw print painted onto the metal.

"– is that it's flammable."

Frankie moans. "I'm going to go make some tea or something." Harriet's okay with this. She doesn't need Frankie for this kind of thing. This is her thing, not his. They both have their niches. Still, sometimes she wonders: Is he losing the taste for this work? Does he really have the stomach for it?

As Frankie exits the room, Mrs. Gaynes remains transfixed by the lighter.

"You're not FBI," the old woman hisses, watching her reflection in the chrome.

"I should clarify," Harriet says. "Oxygen is not exactly flammable. Technically, it's considered an accelerant. That's how fire burns – it feeds on oxygen. It helps flame to spread quickly and efficiently. The problem with the air around us is that the oxygen is diluted. But what you're breathing is the real deal. Incredibly pure. Perfectly concentrated."

"Please," the old woman says.

Harriet's face shows no emotion, but inside, her heart is a leaping gazelle. This is her favorite part of the job. It is a small pulsing center of warmth inside her mind.

"Were I to light a lighter," Harriet continues, "the presence of the tank and the precious oxygen whispering from the tube would help the flame sweep over your frail, withered body. Have you ever seen someone set aflame?"

"My son–"

"Forget him. Think of yourself. I was… on-scene at a car fire. A woman and her husband sat trapped in the car, held fast by crumpled metal and melting seat belts. It was not a quick death. All that screaming. All that thrashing about. Such movement only helps to churn in more oxygen and give the fire more meat for its ragged teeth."

Mrs. Gaynes sobs silently as Harriet pops the tubes from the old woman's nose. From the end of the tubes come a faint susurration: fsssssssss, the sound of something once life-giving, now potentially deadly. Harriet brings the lighter close, pops it, massages it with her thumb.