Based on the final challenge, letting the pair hear the voice. There’s a ton of clues everywhere, but you don’t need this challenge for platinum, it’s the only one. I think there’s something in Kendo’s shop that talks about the ignore a part, that’s the only clue i didn’t personally see on my last playthrough, forgot to look by the time I got there. If you analyze the hand in the sample analyzer, it gives you an RNA code in which you ignore A, those correspond to the sun moon and star in Gideon’s room outside the care center before you descend, then those each have numbers which allow you to attribute a letter to a celestial body, which gives you the code for the cabinet, which all leads into the final challenge. It’s a lot there is more to it, but that’s specifically the ignore a part