The answer is THUJONE The corresponding square is house puzzle by Chris Morse It's all Green to Me by Chris Morse This puzzle shows five molecules that all have a common name. You can easily search them all by formula, and an average college chem student could probably name two of them without looking anything up. Their names are: Left to right, and top to bottom: closantel - C22H14Cl2I2N2O2 codeine - C18H21NO3 hydroquinone - C6H6O2 valine - C4H11NO2 wortmannin - C23H24O If you place each of these into the grid (there is only one proper space), the circled letters spell: VIEW MODEL AT HQ If you come to headquarters, there is a box with a plastic model of a molecule inside using black for carbon, white for hydrogen, and red for oxygen. This molecule has the formula C10H16O. While there are many molecules with this formula, the model is distinctly that of thujone. THUJONE is the answer. Thujone is the major component of absinthe, thus the title, It's All Green to Me.