Now that you have all the cards, including the ace, it's time to make them cough up the secret they carry. Let's go back to Nancy's room and try soaking them again. (It's a little easier if you soak the ace first and then the whole deck.)
This time, the cards reveal their message really fast. All you have to do now is reassemble them. Read to the end of this hint for a screenshot showing how the cards go together.
Left click on a piece to pick it up, right click to rotate it. When you match two pieces correctly, they'll lock together and can be moved as a unit.
The first step to take is to turn all the pieces right-side up, as much as you can. The ones that have only colors give you no clues here, but the ones with letters can be rotated.
Also, this is a chemical formula, so any letter and number combinations will have the numbers hanging down below the letters rather than sticking up above, so that's some help too.
The "HO" or "OH" isn't much help; those letters look the same both ways, and in fact both OH and HO appear in the formula. But you can at least keep them from being sideways.
With the colored hexagons, look for any piece that hits an edge of its card, then look for the rest of that shape on another card. All the hexagons will be complete; there won't be any half hexagons when you're done.
The final assembly of cards won't be a square; in fact, it's going to be an odd irregular shape with sticky-out bits all over.
If you're totally lost, here's the final arrangement of cards:
When Nancy realizes what she's got in her hands, she's frantic to find a safe place to put it, and I don't blame her. But where? Not in the room safe, that's for sure. Head for the elevator while we try to think of a place --
-- and yikes! I have a really bad feeling about this ...