“This is a rush chemical analysis done by Texas Analytic Laboratories,” Mark announced, pointing a silk handkerchief at the top lines on the screen.

“The sample was taken directly from Raymond Callahan’s daily executive thermos on the morning of December ninth.”

Frank Doyle got up out of his leather chair and leaned his heavy frame over the mahogany table to read the screen.

He took his reading glasses out of his coat pocket and put them on.

“Lead acetate,” Frank read out loud, his gravelly voice echoing in the quiet room.

“Concentrated industrial thallium compounds.