Denouement is a French word that translates something to the effect of "tying up loose ends." It is pronounced (day-new-mon(but like the n at the end is dampened and said ever so daintily.)) It helps when trying to pronounce this overly French word around your friends if you eat a crepe and surrender at the same time.
Anyway... This is the end of your book. Kiss it good bye (that is until you go to edit/revise 1,000,041 times.) There are two ways to go here. Happy or sad. Perhaps Rico and Antonia are finally sailing off into the sunset together, in which case this would fit.
But if the world has been turned into a wasteland of zombie/vampire hybrids at the end of which the last two uninfected vampires get infected and turn in each others arms to culminate the end of us all... this might be more appropriate.
This is the end of this series, unless someone has a suggestion I'll just go back to posting a bunch of rocktastic songs to write to. Let me know down below.