Author's Notes: Written for the ds_flashfiction Button Challenge. Thanks again and again, china_shop and sageness, for your always awesome beta.

"Tanacetum vulgare," Fraser said, withdrawing a disposable glove from his belt pouch and snapping it on, in order to collect a sprig of the plant as evidence.

"Gesundheit," said Ray.

Fraser smiled. "Common tansy, or golden buttons. It's a perennial herb of the sunflower family with a long history of medicinal use. Unfortunately, it contains alkaloids that are toxic if consumed in large quantities."

"So old man Carlesson was poisoned, then?" Ray had been sniffing appreciatively at the carafe of coffee on the Carlesson's breakfast table, and he put it down suddenly, causing the contents to slop over the side.

"Well, possibly not deliberately. Human consumption of common tansy has been practiced for centuries with few ill effects. But the toxic properties of the plants are cumulative and long term consumption of large amounts can cause convulsions and even death. The toxicology report should indicate whether it was a single massive dose..."

"Or Mrs Carlesson was adding it to his morning coffee for his good health," Ray snorted.

"Tansy is usually used to treat worms, and has a distinctive bitter after-taste." A window box on the sunny kitchen windowsill contained a number of herbs with various medicinal and culinary properties. Fraser turned away toward the table, dipping his little finger in the carafe to taste the coffee.

"Fraser!"

Ray's outrage amused him, but he could detect nothing beyond the rich taste of dark-roasted beans. "A fine blend of Arabica and Robusta," he said, removing the glove from his other hand before tucking it neatly back into his pouch.

"Well, since we're going to be waiting on that report, how about we go and get you a decent cup then. Me too," Ray amended as Fraser raised an eyebrow.

"C'mon," Ray said. "We can get it to go, if you want."

Fraser picked up the evidence bag from the table and examined the sturdy stem with its flat-topped cluster of yellow flowers. He thought about how its toxicity was countered by its usefulness. How, in moderation, even a deadly poison had a purpose. He looked up as Ray's hand fell on his shoulder.

"You got worms? Or should we take some with us for Dief?" A warm, teasing note in Ray's voice gave Fraser a nervous glow in his stomach, as if a dozen fireflies were trapped there. Love and an inner ear imbalance might have similar symptoms - dizziness, vertigo, nausea - but the latter was frequently due to dehydration and easily treatable. He ignored the tease in favor of the invitation.

"All right. I think I'll have my coffee with a large glass of water." Fraser drew fresh courage from the fact that Ray kept a hand on his shoulder until they reached the car, talking warmly in his ear the whole time.

He wasn't the man he once was. He could tell the difference now between love and an inner ear imbalance. And if his symptoms persisted, he suspected Ray could be convinced to help him find, if not a cure, at least a treatment.