Aramis becomes the Man in the Iron Mask in Versailles (2015)
- In Versailles s3, it's revealed that the Man in the Iron Mask is the biological father of Louis XIV and his younger brother Philippe Duc D'Orleans. Aramis' affair with the Queen results in the birth of Louis XIV, so it's possible they could have slept together again to create Philippe (though with some historical liberty on the timeline, since Philippe was only 2 years younger than Louis, and there's no sign of him after a 4 year time skip in the Musketeers). Then to hide that secret he's locked in the Bastille.
Milady will murder the Cardinal at the start of or prior to series two.
- It can be her last act of vengeance for throwing her to the Musketeers after her years of service. Plus, it would be a clean way to explain Peter Capaldi's absence from the show, assuming he won't be brought back after he's done with Doctor Who.
The Cardinal is just in hiding
We never see his body, and it's never indicated if any else saw what was buried either.
The Dauphin's governess, Marguerite, is a Spanish spy.
Her seduction by Aramis seems a slight departure from his usual Chivalrous Pervert
modus operandi (since his motive seems to be purely to use her to gain proximity to the Dauphin) and this could play out in one of several of ways.
- Aramis could fall genuinely in love with her and feel betrayed when her true allegiance is revealed.
- She could fall genuinely in love with Aramis and decide to betray her masters who kill her in reprisal. Whether or not Aramis also falls in love with her, he would be shattered by remorse and self-recrimination.
- She just gets revealed as a spy and a traitor (and possibly a threat to the Dauphin) and Aramis get to play the Karma Houdini card.
- The Musketeers discover her true allegiance and deceive her into revealing a Spanish plot or helping them in some other way (a bit like their ploy to deceive Milady and the Cardinal in the series 1 finale).
Rochefort's treason will never be revealed.
- Milady will kill him for her own reasons, without the main characters ever finding out he was their enemy.
Season two will follow the canon ending of the books
- Mainly, Milady killing Constance and Athos having to kill her once and for all. For one thing, Constance and D'Artagnan have finally admitted their feelings for each other, and Athos and Milady have...not quite reconciled, but their toxicity has reduced. Everything seems to be going well, and so it will all end horribly.
- Happily and completely jossed. Milady actually undegoes something of a HeelFace Turn and leaves France, while D'Artagnan and Constance get married! Though, there's still season three...
The last episode will have the King die
- And the Musketeers step forward as the episode ends with the Queen becoming regent.
Cardinal Richelieu is a Time Lord.
- More specifically, the Valeyard, who looks like the Twelfth Doctor because they have the same genetic code, and thus are more likely to regenerate into the same form.