Rachel Summers and Nightcrawler have their morning ruined when Mesmero arrives and manipulates former's mind. Meanwhile, Kitty Pryde and Colossus are still reeling from their cancelled wedding when we suddenly jump to a future where mutants are on the edge of extinction thanks to the Sentinels.
That time jump happens just as abruptly in the comic itself. We're witnessing the complex and muddled emotions of Kitty and Colossus, and then we are suddenly in a mutant concentration camp in the future.
It's technically foreshadowed and explained, but the sequencing of it is a bit of a disjointed mess. It's fully explained at the end, but, again, the sequencing of it doesn't make a lot of logical sense.
That future resembles that of Days of Future Past, but it's worth mentioning how often this premise has been retread, especially given that the previews for Extermination look a lot like Days of Future Past.
That future digression doesn't add too much to the comic. It interrupts the Piotr and Kitty plot. It is intended to show what a certain character is seeing, but you can't help but wonder why this vision is so extensive and what some of it actually adds to the story.
Pere Perez's artwork is solid, giving something of a classic feel to the aesthetics of the comic. The detailing is deliberate and only as extensive as needed. There are plenty of good-looking panels, with Mesmero getting an impressive splash page to himself. The future scenes have a decent design too. Jay David Ramos and Matt Milla provide a well-balanced color palette throughout the comic, though some pages feel a little oversaturated.
X-Men Gold #31 is a cul-de-sac of a story. There's little to be taken to this Days of Future Past flashback beyond the shallowest of nostalgic digressions. It's not terrible, but it is dull and vanilla. I can't recommend this one. Give it a pass.