Chris' dad purchases a ring (actually a Chaos Emerald) in a jewelry store intending for it to be a gift to Chris' mom for their wedding anniversary. On that day, while she is filming in the studio, he calls Chris, Chuck, the leader of S-Team etc. there and secretly plans a flashy surprise party, but having noticed the (purple) Chaos Emerald, Eggman, as well as Rouge and Topaz, surge in as well and cause mayhem. (thetvdb.com)