In these stash-house cases, the Government’s “participation in the offense conduct” is what makes them particularly repugnant to the Constitution. Everything about the scheme—and therefore almost everything bearing upon a defendant’s ultimate sentence—hinges solely on the Government’s whim. Why were there not 10 kilograms in the stash house? Or 100? Or 1,000? Why were the guards allegedly armed—necessitating that Defendants bring weapons along with them? All of these factors came down to the ATF and the undercover agent alone. That sort of arbitrariness offends the Constitution’s due-process demands.