I think that this one would be a good one to follow up on.
"They can inspect the dining room with the magnifying glass, and discover traces of a fine black sand tracked into the spaces between floorboards. If someone, for some reason, decides to test the black sand for poison, they’ll find that only one of the two liquids turns blue, and Lien won’t be able to tell them why. They can follow up on how the chemicals work at Stark Industries if they’d like."
CRIME #3: TEAM PLOTTING
"They can inspect the dining room with the magnifying glass, and discover traces of a fine black sand tracked into the spaces between floorboards. If someone, for some reason, decides to test the black sand for poison, they’ll find that only one of the two liquids turns blue, and Lien won’t be able to tell them why. They can follow up on how the chemicals work at Stark Industries if they’d like."