This story is a sequel to Spike's Frontier
Some time has passed since Spike defeated The End alongside Sonic during the events of the Starfall Islands, it was an important point in his life that changed things for him, since they're reunion, Spike's been trying to reconnect with his mother Angel, who's still trying to adjust being with her son again after thousands of years, both of them have had a lot to go through, yet there's still so much Spike has to learn about himself, and his mother.
But during Spike and Angel's time to themselves, they are attacked by a strange monster called the Time Eater. They both get pulled into different points in time, for Angel, she ended up in a white void that is full of old places from Sonic's past, and soon meets up with two versions of Sonic from both the past and present, and she teams up with the both of them to stop the monster from erasing space and time.
But as for where Spike ended up, he ends up meeting another hedgehog known as Shadow at an earlier point in time, after they try figuring out what's going on, they conclude that there's a bigger tie into this then they thought, and as they head towards the Space Colony Ark to investigate a returning threat with the help of Shadow's friends, this sends them on a journey beyond both time and space through both they're history's in order to stop this threat and help Spike get home with his mother, and stop the monsters that threaten they're home.