Basically it's the same as the previous Sonic #98 spoilers, but some other information is given.
Written by Karl Bollers and Ken Penders, art by James Fry, Ron Lim and Penders.
"Blow By Blow" After returning to Knothole, Geoffrey informs Elias that Robotnik still has robotization on his mind. Sally disguises herself as a servant and manages to sneak out of Castle Acorn in order to go see Sonic, but Sonic has his hands full trying to stay incognito while he continues his quest for Arachnis and the Sword - not to mention Mina, Sally's latest rival for Sonic's affections. The intrigue never ends where Kodos, Doctor Quack, Tails, Nate, Elias and Knuckles all play a part. Plus, another Knuckles back-up story, this time guest-starring Sonic's buddy Tails.
32 pages, $1.99, arrives in stores on June 29.
Source: Comics Continuum
Note: The information on the back-up is wrong since "Chosen One" arc ends in Sonic #97 and the back-up in Sonic #99 is going to be a story called "What Goes Around Comes Around!" which will mark the return of Julie-Su and the Dark Legion.