VERY rudimentary, Salzmank-is-spitballing outline for the book:
A short song number introduces each major hero, with a leitmotif that follows him throughout the show. Briefly, we see them getting together, fighting the alien threat in the first movie, etc. Note: We have to keep it down to the original team-members in the first movie (undecided on Renner and Johansson’s characters). All seems well, but tensions are rising b/w the team members.
On another planet, enter Thanos: we quickly realize we’ve been seeing the Avengers through
his eyes the entire time. Sings uplifting love song that says his love will bring peace to the cosmos, but we gradually realize he’s singing to Death, and “peace” means annihilating half the universe. Destroys planet he’s on, announces Earth is next.
Arrives, fights Avengers. All begin quest for stones. At some point, murders daughter, who here starts off as a loyal lieutenant but now is beginning to question Dad; otherwise, Guardians of Galaxy not in this (plot difficult enough to adapt already). This is not as in-depth as in the movie.
Song sequence for Thanos as he puts gems in glove, music builds up to his snapping fingers. The snapping takes the place of what would have been the final sung note. Stage lights wild. Curtain on Act I.
Act II, gloomier stage. Thanos enters. He sings again to Death, who appears à la Queen of the Night in
The Magic Flute. He thinks he has won her heart, but she spurns him, says (sings) half the universe is not enough to win her love. First traces of doubt in Thanos.
Earth is rebuilding after the Thanos snap. Thor is not on earth, and another of the Avengers should have been “snapped” out of existence. People turn on heroes, reports of governments passing laws against Avengers. Thor returns, tells the others that Thanos is doing Death’s bidding (Death here = the Norse Hel). At Thanos’ arrival, he plans to finish the job, Avengers attack, Thanos swats them away—but then he sees Stark protecting his daughter and reconsiders his allegiance to Death. (I’m thinking here of Dr. Manhattan’s reevaluation of life in
Watchmen.) Thanos is the one who turns on Death and snaps his fingers again, now bringing back the world as it used to be. He gives his life up to Death instead of all he has killed. (Wasn’t intending him as Christ figure, but nonetheless that’s probably how audiences will take it.)
End on a positive note, but nevertheless it’s not the heroes who saved the day; it’s really Thanos’ change of heart. Question is, what are the positives and negatives of heroism? This is different enough, I think, to surprise fans and audiences, but it’s not
too different from source.