After a graduate student is asked to identify a body—his pot-dealer’s, he enlists the help of two other clients to give the man a proper burial.
Sound like an interesting seed idea for a story. But what it may grow into, I don’t know. Have you ever asked your husband WHY he didn’t open it?
Be that as it may, I suggest the principle of “Chekhov’s gun” applies. If a gun is introduced in the 1st Act, it has to be fired in the 2nd. By extrapolation, if you’re going to introduce the envelope as an important prop in the 1st Act, you have to pay it off by the end of the film.
How do you want to pay it off?