Well this one's a bit unexpected, not so much in terms of the transfer itself, but in terms of timing.
After an entire soap opera's worth of drama this summer, Mohamed Salah eventually ended up on loan at AS Roma. While Roma did have the option to buy the player as well, it was understood that this option would only come into effect next summer. Turns out, it has come into effect already. And it's been redeemed already.
"Among the most significant transactions of the summer transfer campaign of the sporting season 2014/2015, conducted from July 1 to August 31, 2015 were:
The acquistion on permanent basis of the rights of players Dzeko of Manchester City, Salah of Chelsea and Falque from Genoa. For these players there were initially signed agreements to be acquired on temporary basis, became permanent following the verification, during the first months, of the contractual conditions previously set."
-AS Roma statement via KingFut
Mohamed Salah (and Edin Dzeko and Iago Falque) are all Roma players now, not just loanees. Here's the actual financial statement (in Italian) that Roma are required to publish as a publicly traded company.
Roma reveal Dzeko, Salah, and Falque are now permanent transfers pic.twitter.com/iApSIvbErI— John Solano (@Solano_56) October 1, 2015
For what it's worth, the original agreement published makes no mention of this possibility of an early redemtion. Combine that with the potential legal action still forthcoming from jilted Fiorentina, their lawyers, and FIFA, and there's still plenty of room left for more drama.
UDPATE: Chelsea's version of the initial loan includes the provision to make the move permanent "at any point" during the season. So there we go.
Meanwhile, Salah's off to a good start once again in the Serie A, having scored 3 times in 6 league matches already. There's no word yet on how much Roma ended up paying altogether, but they had already forked out €5m just for the initial loan. At the time of the loan move, Di Marzio claimed that the option to buy would be an additional €15m.
In any case, good luck the rest of the season... and the rest of your career, Mohamed Salah! It's been real.